41 research outputs found
Тепловая экономичность привода питательных насосов электростанций
In the production of micro devices the surface properties become more and more important for chemistry, biotechnology and medical technology with respect to wetting properties and chemical composition of the surface. Typical applications are implants as well as micro fluidic systems or miniaturized devices for DNA- and proteome analysis (biochips). In this paper newly designed laser technologies based on UV-laser treatment of polymers for surface processing are described to manipulate wetting properties, cell growth and immobilization of functional molecules with high spatial resolution. Depending on the processing parameters and used polymers either hydrophobic or hydrophilic properties can be enhanced (i.e. laser induced lotus/anti-lotus effect). Enhanced roughness and changes of the chemical composition have also influence on cell growth on polymer surfaces. Thus guiding aids for cells e.g. on medical implants can be generated by laser irradiation. Due to photo oxidation processes while UV-treatment in air, functional groups are created that are suited for covalent bonding of (bio)moelcules onto the surfaces. A second process for the locally selective immobilization of anchor molecules based on azide functionalized templates suitable for further modification steps is presented by means of irradiating polymers under solutions of these linkers
Use of an amplatzer vascular plug in embolization of a pulmonary artery aneurysm in a case of hughes-stovin syndrome: a case report
<p>Abstract</p> <p>Introduction</p> <p>Hughes-Stovin syndrome is a rare condition characterized by peripheral deep venous thrombosis accompanied by single or multiple pulmonary arterial aneurysms. The limited number of cases has precluded controlled studies of the management of pulmonary artery aneurysms, which usually cause massive hemoptysis leading to death. This is the first report of a new endovascular treatment of a single large pulmonary arterial aneurysm.</p> <p>Case presentation</p> <p>An 18-year-old Caucasian man was referred to our department with recurrent severe hemoptysis. His medical history included Hughes-Stovin syndrome diagnosed during a recent hospital admission. The patient was initially treated with corticosteroids. Because of his recurrent hemoptysis, we decided to embolize a 3.5 cm pulmonary arterial aneurysm using an Amplatzer Vascular Plug. The procedure was not complicated, and the patient's post-intervention course was uneventful. The patient has remained free from any complications of the embolization 36 months after the procedure.</p> <p>Conclusion</p> <p>Percutaneous embolization of a single large pulmonary artery aneurysm with an Amplatzer Vascular Plug in a patient with Hughes-Stovin syndrome is a less invasive procedure that represents the best multidisciplinary approach in treating these patients.</p
Adaptive Coding and Packet Rates for TCP-Friendly VoIP Flows
If low-rate VoIP is transmitted over congested links, both the coding and the packet rate need to be adapted to achieve the best conversational quality: On an Ethernet network it is better to jointly change packet rate and speech coding rate; in WLAN networks it is sufficient to change the packet rate. We also study whether TCP-friendly rate control algorithms are suitable for dynamically adapting packet and coding rate of a VoIP flow. Our results show that cannot be used for VoIP applications as they only control the packet rate do not consider packet sizes. Also, they do not transmit small (speech) packets fairly. We present an enhanced version of the TCP friendly rate control (TFRC) protocol that transmits small packets fairly and evaluate it with network simulations
El Ditirambo 18 de Baquílides: estudio composicional y métrico
El Ditirambo 18 de Baquílides: estudio composicional y métric