Shortage of autologous blood vessel sources and disadvantages of synthetic grafts have increased interest in the development of tissue-engineered vascular grafts. However, tunica media, which comprises layered elastic laminae, largely determines arterial elasticity, and is difficult to synthesize. Here, we describe a method for fabrication of arterial grafts with elastic layer structure from cultured human vascular SMCs by periodic exposure to extremely high hydrostatic pressure (HP) during repeated cell seeding. Repeated slow cycles (0.002 Hz) between 110 and 180 kPa increased stress-fiber polymerization and fibronectin fibrillogenesis on SMCs, which is required for elastic fiber formation. To fabricate arterial grafts, seeding of rat vascular SMCs and exposure to the periodic HP were repeated alternatively ten times. The obtained medial grafts were highly elastic and tensile rupture strength was 1451 ± 159 mmHg, in which elastic fibers were abundantly formed. The patch medial grafts were sutured at the rat aorta and found to be completely patent and endothelialized after 2.5 months, although tubular medial constructs implanted in rats as interpositional aortic grafts withstood arterial blood pressure only in early acute phase. This novel organized self-assembly method would enable mass production of scaffold-free arterial grafts in vitro and have potential therapeutic applications for cardiovascular diseases.
The concept and configuration of a plasmonic cascadable full adder are proposed, whose logic operation is carried out by interference of surface plasmons and whose circuits are formed only with single-and multiple-mode plasmonic waveguides. This full adder is fabricated by patterning a SiO 2 film deposited on a metal film using complementary metal-oxide-semiconductor-compatible processes except for the material of metal. The redundant surface plasmons present after interference are drained from the waveguides by forming radiation ports, and metal bumps are formed in the circuits to prevent stray light recoupling with the waveguides. The logic operation of the circuits is numerically confirmed by the three-dimensional finite-difference time domain method, and the difference in surface plasmon intensity between logic level "0" and "1" is numerically estimated to be 1.5 dB even for the worst case. These simulations were experimentally confirmed for some input signal patterns using scanning near-field microscopy, and the surface plasmon intensity distributions monitored coincide well with those simulated.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.