How to Quantize Forces(?): An Academic Essay How the Strings Could Enter Classical Mechanics

Geometrical formulation of classical mechanics with forces that are not necessarily potential-generated is presented. It is shown that a natural geometrical "playground" for a mechanical system of point particles lacking Lagrangian and/or Hamiltonian description is an odd dimensional line element contact bundle. Time evolution is governed by certain canonical two-form $\Omega$ (an analog of dp/\dq-dH/\dt), which is constructed purely from forces and the metric tensor entering the kinetic energy of the system. Attempt to "dissipative quantization" in terms of the two-form $\Omega$ is proposed. The Feynman's path integral over histories of the system is rearranged to a "world-sheet" functional integral. The "umbilical string" surfaces entering the theory connect the classical trajectory of the system and the given Feynman history. In the special case of potential-generated forces, "world-sheet" approach precisely reduces to the standard quantum mechanics. However, a transition probability amplitude expressed in terms of "string functional integral" is applicable (at least academically) when a general dissipative environment is discussed.Comment: 13 pages, 3 pictures, comments are welcom

Refinement of Animal Experiments: Replacing Traumatic Methods of Laboratory Animal Marking with Non-Invasive Alternatives

Reliable methods for identifying rodents play an important role in ensuring the success of preclinical studies. However, animal identification remains a trivial laboratory routine that is not often discussed, despite the fact that more than 6 million rodents are used in animal studies each year. Currently, there are extensive regulations in place to ensure adequate anesthesia and to reduce animal suffering during experiments. At the same time, not enough attention is paid to the comfort of rodents during routine identification procedures, which can be painful and cause some complications. In order to achieve the highest ethical standards in laboratory research, we must minimize animal discomfort during the identification phase. In this article, we discuss traumatic methods of identification and describe several painless methods for marking in long-term experimental studies. The use of non-traumatic and non-invasive methods requires the renewal of marks as they fade and additional handling of the rodents. Laboratory personnel must be trained in stress-minimizing handling techniques to make mark renewal less stressful

Post-Implantation Inflammatory Responses to Xenogeneic Tissue-Engineered Cartilage Implanted in Rabbit Trachea: The Role of Cultured Chondrocytes in the Modification of Inflammation

Immune responses to tissue-engineered grafts made of xenogeneic materials remain poorly studied. The scope of current investigations is limited by the lack of information on orthotopically implanted grafts. A deeper understanding of these processes is of great importance since innovative surgical approaches include the implantation of xenogeneic decellularized scaffolds seeded by cells. The purpose of our work is to study the immunological features of tracheal repair during the implantation of tissue-engineered constructs based on human xenogeneic scaffolds modified via laser radiation in rabbits. The samples were stained with hematoxylin and Safranin O, and they were immunostained with antibodies against tryptase, collagen II, vimentin, and CD34. Immunological and inflammatory responses were studied by counting immune cells and evaluating blood vessels and collagen. Leukocyte-based inflammation prevailed during the implantation of decellularized unseeded scaffolds; meanwhile, plasma cells were significantly more abundant in tissue-engineered constructs. Mast cells were insignificantly more abundant in tissue-engineered construct samples. Conclusions: The seeding of decellularized xenogeneic cartilage with chondrocytes resulted in a change in immunological reactions upon implantation, and it was associated with plasma cell infiltration. Tissue-engineered grafts widely differed in design, including the type of used cells. The question of immunological response depending on the tissue-engineered graft composition requires further investigation

XFEL RF Input Power Coupler Thermal Analysis

XFEL RF input power coupler thermal analysis was performed for different coupler inner conducting surfaces plating

Development of Key Technologies for Power Coupler Manufacturing

Fundamental Power Coupler (FPC) is an interface between High Power RF (HPRF) – an RF Power Source(Klystron, IOT, SSA etc.) with its power distribution system (waveguides) and Accelerating Cavity.FPCs for SRF cavities are among the most important and most complicated auxiliary systems insuperconducting particle accelerators. Successful FPC design uses modular approach, standard materials(steel, copper, ceramics etc.), standard sizes (tubes, bellows, flanges) and standard manufacturingtechniques (welding, brazing, plating etc.). New fabrication methods emerge and may be effectivelyapplied. Classic well known techniques are being developed as well. Close collaboration withindustry is necessary: manufacturing problems can be solved in a prototype or pre series fabrication