Sökresultat

Variable time-step methods, with general step-size control objectives, are developed within the framework of variational integrators. This is accomplished by introducing discrete transformations similar to Poincares time transformation. While gaining from adaptive time-steps, the resulting integrators preserve the structural advantages of variational integrators, i.e., they are symplectic and mome

The human anaphylatoxin peptide C3a, generated during complement activation, exerts antimicrobial effects. Phylogenetic analysis, sequence analyses, and structural modeling studies paired with antimicrobial assays of peptides from known C3a sequences showed that, in particular in vertebrate C3a, crucial structural determinants governing antimicrobial activity have been conserved during the evoluti

Caspase 3 staining in Schwann cells was investigated with immunohistochemistry, as a measure of Schwann cell apoptosis, after transection and immediate (day 0) or delayed rat sciatic nerve repair (30, 90 and 180 days post injury). Cleaved caspase 3 stained Schwann cells significantly increased at the site of lesion (SNL; median [IQR], 15.2 [7.0] %) and in the distal nerve segment (SND; 9.5 [3.6] %

Five protected analogues of beta-D-galctosyl-(5R)-5-hydroxy-L-lysine were prepared, in which the galactosyl moiety was modified by monodeoxygenation or inversion of stereochemistry at C-4. The building blocks were used in the solid-phase synthesis of a set of glycopeptides related to the peptide fragment CII256-273 from type II collagen. Evaluation of the glycopeptides revealed that T-cell hybrido

Using a primitive model approach, we analyze the influence of ion specific adsorption on the phase behavior of charged lamellar systems. The presence of a weak short-ranged surface potential, attracting monovalent counterions, induces a phase separation, where the separate phases have different repeat distance. If the adsorption potential is very weak, the more narrow phase never forms. An opposit

A four-year study of species composition of the zooplankton community was conducted at Lagoa Comprida, a coastal lagoon. Forty-two species of rotifers were recorded and illustrated. All rotifer species, except Lecane boettgeri Koste, 1986 and Macrochaetus kostei, Jose de Paggi, Branco & Kozlowsky-Suzuki, 2000, have already been found in other areas of Brazil. Some factors, which probably favor

The detrusor smooth muscle is the main muscle component of the urinary bladder wall. Its ability to contract over a large length interval and to relax determines the bladder function during filling and micturition. These processes are regulated by several external nervous and hormonal control systems, and the detrusor contains multiple receptors and signaling pathways. Functional changes of the de

Myelodysplastic syndromes (MDSs) are a group of hematopoietic stem cell disorders characterized by ineffective hernatopoiesis and peripheral blood cytopenias. Lenalidomide has dramatic therapeutic effects in patients with low-risk MDS and a chromosome 5q31 deletion, resulting in complete cytogenetic remission in >60% of patients. The molecular basis of this remarkable drug response is unknown. To

We calculate the linear chirp rates of high-order harmonics in argon, generated by intense, 810 nm laser pulses, and explore the dependence of the chirp rate on harmonic order, driving laser intensity, and pulse duration. By using a time-frequency representation of the harmonic fields we can identify several different linear chirp contributions. to the plateau harmonics. Our results, which are bas

We show that; one can count k-edge paths in an n-vertex graph and m-set k-packings on an n-element universe, respectively, in time (n k/2) and (n mk/2) up to a factor polynomial in n, k, and in: in polynomial space, the bounds hold if multiplied by 3(k/2) or 5(mk/2), respectively. These are implications of a more general result: given two set families on an n-element universe, one can count the di

A new design of robust matrices for cell immobilization is described. Macroporous gels (MGs) with immobilized microbial cells were prepared at subzero temperatures and were formed inside a plastic core (so-called, protective housing). Due to the protective housing the macroporous gel particles with immobilized cells can be used in well-stirred bioreactors. High retained activity of yeast (77-92%)

A model is developed using a thermal network analysis approach. An experimental setup is designed and built to validate the model. The model is based on an inverse thermal network analysis using a singular value decomposition algorithm. The data from the experiments are used to determine the thermal conductances using inverse model's unsteady- and steady-state forms. The model development and expe

Imaging of technical and biological objects using hard X-rays from a laser-produced plasma source is demonstrated. Magnification radiography and single-shot imaging of biological samples are feasible with the source, which utilised focused radiation from a short-pulse terawatt laser. Differential imaging with element specificity and a new projection geometry for X-ray radiography are proposed.

Genetic variation in female resistance and tolerance to male mating harassment can affect the outcome of sexually antagonistic mating interactions. We investigated female mating rates and male mating harassment in natural populations of a damselfly (Ischnura elegans). This damselfly species has a heritable sex-limited polymorphism in females, where one of the morphs is a male mimic (androchrome fe

A new processing scheme for the fabrication of sub-100-nm-gate-length vertical nanowire transistors has been developed. InAs transistors with an 11 x 11 nanowire matrix and 80 nm gate length have been realized by this process. The gate length is directly controlled via the thickness of the evaporated gate metal and is thus easily scalable. The demonstrated devices operate in depletion mode, and th

Heme A, as a prosthetic group, is found exclusively in respiratory oxidases of mitochondria and aerobic bacteria. Bacillus subtilis CtaA and other heme A synthases catalyze the conversion of a methyl side group on heme 0 into a formyl group. The catalytic mechanism of heme A synthase is not understood, and little is known about the composition and structure of the enzyme. In this work, we have: (i

Density functional theory is used to study polymer solutions between surfaces in equilibrium with a bulk solution. We investigate the effect on the surface interaction free energy of having star polymers with different numbers of arms. In addition, we consider the role played by the strength of the adsorption potential and the concentration of the polymer molecules. The interaction free energy is