Generate a file for use with external citation management software. Epub Nov Abstract Atrial fibrillation AF is the most common sustained arrhythmia.
Development[ edit ] SA-2 Guideline missile on display at the National Air and Space Museum In the early s, the United States Air Force rapidly accelerated its development of long-range jet bombers carrying nuclear weapons. The range, speed, and payload of these U.
Rear view showing the solid-propellant booster nozzle, as displayed in Imperial War Museum Duxford Consequently, the Soviets initiated the development of improved air defence systems. Although the Soviet Air Defence Forces had large numbers of anti-aircraft artillery AAAincluding radar-directed batteries, the limitations of guns versus high-altitude jet bombers were obvious.
This program focused on producing a missile which could bring down a large, non-maneuvering, high-altitude aircraft.
As such it did not need to be highly maneuverable, merely fast and able to resist aircraft counter-measures. For such a pioneering system, development proceeded rapidly, and testing began a few years later. Inthe wider public first became aware of the S when the missile was shown at that year's May Day parade in Moscow.
Initial deployment[ edit ] Wide-scale deployment started inwith various upgrades following over the next few years. Between mid andU. These sites tended to cluster around population centers, industrial complexes, and government control centers. A ring of sites was also located around likely bomber routes into the Soviet heartland.
By the mids, the Soviet Union had ended the deployment of the S with perhaps 1, operational sites. In addition to the Soviet Union, several S batteries were deployed during the s in East Germany to protect Soviet forces stationed in that country.
The aircraft was hit by a Chinese-operated S site near Beijing on October 7, The first missile destroyed the U-2, and a further 13 were also fired, hitting a pursuing high-altitude MiG That action led to the U-2 Crisis of The decision was not made lightly, because it greatly increased the chances that one would fall into US hands for study.
Site preparation started early in the year, and the US detected the program almost immediately on 5 April Most of the S were deployed around the Hanoi - Haiphong area and were off-limits to attack as were local airfields for political reasons.
The missile system was used widely throughout the world, especially in the Middle Eastwhere Egypt and Syria used them to defend against the Israeli Air Forcewith the air defence net accounting for the majority of the downed Israeli aircraft. The last success seems to have occurred during the War in Abkhazia —when Georgian missiles shot down a Russian Sukhoi Su fighter near Gudauta on March 19, Countermeasures and counter-countermeasures[ edit ] Between and earlythe Vietnamese had nothing to threaten American pilots in the air.
However, after S shot down some of U. S aircraft, the U. S bombers began to descend below three kilometers. But at an altitude, the Vietnamese waited them for the anti-aircraft guns .
Between andthe US delivered countermeasures to the S problem. The Air Force fitted B bombers with powerful jammers which blinded the early warning radars and by developing smaller jamming pods for fighters which denied range information to the radars. Later developments included the Wild Weasel aircraft, which were fitted with anti-radiation air-to-surface missile systems made to home in on the radar from the threat.
This freed them to shoot the sites with Shrikes of their own. The Soviets and Vietnamese were able to adapt to some of these tactics. They also introduced a passive guidance mode, whereby the tracking radar could lock on the jamming signal itself and guide missiles directly towards the jamming source.
This also meant the SAM site's tracking radar could be turned off, which prevented Shrikes from homing in on it. Some new tactics were developed to combat the Shrike.
One of them was to point the radar to the side and then turn it off briefly.
Since the Shrike was a relatively primitive anti-radiation missile, it would follow the beam away from the radar and then simply crash when it lost the signal after the radar was turned off. SAM crews could briefly illuminate a hostile aircraft to see if the target was equipped with a Shrike.
If the aircraft fired one, the Shrike could be neutralized with the side-pointing technique without sacrificing any Ss.The International Pharmaceutical Excipients Council Europe "The future of excipients is in our hands".
Dear Colleagues, We are pleased to invite you to attend the 18th International Congress on Neutron Capture Therapy (ICNCT) to be held in Taipei, Taiwan, from October 28 to November 2, Guidelines for Working in Taiwan. As the statistics of Filipinos employed in Taiwan rise and as the window of opportunities in the said country widens; tips and information about working in Taiwan becomes a necessity.
Taiwan CDC also updated the guideline on preventing novel coronavirus (MERS-CoV) in healthcare facilities, revised infection control guidelines of MDROs, and released prevention handbooks of methicillin-resistant Staphylococcus aureus (MRSA), and carbapenem-resistant Acinetobacter baumannii (CRAB).
Guidelines of the Taiwan Heart Rhythm Society and the Taiwan Society of Cardiology for the management of atrial fibrillation. This information leaflet prepared by the Immigration Department of the Hong Kong Special Administrative Region Government (HKSARG) sets out the visa/entry permit requirements for persons wishing to enter the Hong Kong Special Administrative Region (HKSAR) of the People's Republic of China (PRC).