Two Counter-moving Light Beams

The cylindrically symmetric field of two beamsof light shining in opposite directions is studied. Wepresent four static or stationary exact solutions of thecorresponding field equations and compare their properties.     

Artificial vascular implants from bacterial cellulose: preliminary results of small arterial substitutes

The biomaterial bacterial cellulose (BC) represents an innovative approach for overcoming reconstructive problems associated with extended vascular diseases by providing small caliber vascular grafts (diameter 1.0–3.7, length 5.0–10.0, and wall-thickness 0.7 mm). In a first microsurgical study, the BC implants were attached in an artificial defect of the carotid artery of rats for 1 year. These long term results show the incorporation of the BC under formation of neointima and ingrowth of active fibroblasts. In a second study, the grafts were used to replace the carotid arteries of pigs. After 3 months, these grafts were removed and analyzed both macro- and microscopically. Seven grafts (87.5%) were patent whereas one graft was found occluded. These data indicate that the innovative BC engineering technique results in the production of stable vascular conduits and confirm a highly attractive approach to in vivo tissue engineered blood vessels as part of programs in cardiovascular surgery.     

Nanocellulose Materials – Different Cellulose,Different Functionality

Summary: Nanocelluloses combine in a very exciting manner important properties of cellulose with amazing features of nano-scale materials. With a view to the increasing discussion on the potential risks of nanoparticles and nanotechnology to human health and the environment, it is important to point out that the nanocellulose fibers are irreversibly networked in the supramolecular cellulose structure. This contribution assembles the current knowledge in research, development, and application in the field of nanocelluloses through examples. The topics combine selected results on nanocelluloses from bacteria and wood as well as the formation and in situ shaping of cellulose bodies, the coating of materials with nanosized cellulose networks/supports, and the preparation of nanocellulose composites as well as the use of bacterial cellulose as novel type of medical implants.     

Ligand amplification in a dynamic combinatorial glycopeptide library

N-acetyl glucosamine binding protein amplifies the concentration of one member in a dynamic combinatorial glycopeptide library based on exchanging disulfides.     

Measurement of G(E(p))/G(M(p)) in e(-->)p---> e(-->)p to Q(2) = 5.6 GeV(2)

The ratio of the electric and magnetic form factors of the proton G(E(p))/G(M(p)), which is an image of its charge and magnetization distributions, was measured at the Thomas Jefferson National Accelerator Facility (JLab) using the recoil polarization technique. The ratio of the form factors is directly proportional to the ratio of the transverse to longitudinal components of the polarization of the recoil proton in the elastic e(-->)p---> e(-->)p reaction. The new data presented span the range 3.5< Q(2)< 5.6 GeV(2) and are well described by a linear Q(2) fit. Also, the ratio sqrt[Q(2)] F(2(p))/F(1(p)) reaches a constant value above Q(2) = 2 GeV(2).     

Interaction and dynamics of defects in convective roll patterns of anisotropic fluids

We present an overview of the dynamics and interaction of defects in roll patterns of electroconvection in nematic liquid crystals (EHC). For the decay of an Eckhaus-unstable pattern we distinguish three regimes, depending on the width of the system perpendicular to the wavenumber mismatch. Motivated by recent experiments, we examine the annihilation process of defects in patterns with wavenumber near to band center, where the motion of the defects is dominated by the interaction. The comparison with the experiments shows that this process can be described even quantitatively within the framework of Ginzburg-Landau theory.