In vivo examination of the local inflammatory response after implantation of Ti6Al4V samples with a combined low-temperature plasma treatment using pulsed magnetron sputtering of copper and plasma-polymerized ethylenediamine

Copper (Cu) could serve as antibacterial coating for Ti6Al4V implants. An additional cell-adhesive layer might compensate Cu cytotoxicity. This study aimed at in vitro and in vivo evaluation of low-temperature plasma treatment of Ti6Al4V plates with Ti/Cu magnetron sputtering (Ti6Al4V–Ti/Cu), plasma-polymerized ethylenediamine (Ti6Al4V–PPEDA), or both (Ti6Al4V–Ti/Cu–PPEDA). Ti6Al4V–Ti/Cu and Ti6Al4V–Ti/Cu–PPEDA had comparable in vitro Cu release and antibacterial effectiveness. Following intramuscular implantation of Ti6Al4V–Ti/Cu, Ti6Al4V–PPEDA, Ti6Al4V–Ti/Cu–PPEDA and Ti6Al4V controls for 7, 14 and 56 days with 8 rats/day, peri-implant tissue was immunohistochemically examined for different inflammatory cells. Ti6Al4V–PPEDA had more mast cells and NK cells than Ti6Al4V, and more tissue macrophages, T lymphocytes, mast cells and NK cells than Ti6Al4V–Ti/Cu–PPEDA. Ti6Al4V–Ti/Cu had more mast cells than Ti6Al4V and Ti6Al4V–Ti/Cu–PPEDA. Results indicate that PPEDA-mediated cell adhesion counteracted Cu cytotoxicity. Ti6Al4V–Ti/Cu–PPEDA differed from Ti6Al4V only for mast cells on day 56. Altogether, implants with both plasma treatments had antibacterial properties and did not increase inflammatory reactions.     

Surface design using triangular patches

Surfaces designed in a computer graphics environment have many applications, including the design of cars, airplanes, shipbodies and modeling robots. The generation of smooth surfaces from a set of three-dimensional data points is a key problem in the field of Computer Aided Geometric Design. An overview of fundamental triangular concepts is given and new results are presented.     

Numerical Flow Simulation of Viscoplastic Slurries and Design Criteria for a Tape Casting Unit

Numerical simulations have been carried out using the finite element method (FEM) for the forming flow of ceramic tapes. The flow domain encompasses both the slurry reservoir and the doctor-blade region with free surface and is fully two-dimensional. The material of this study is an organic-bonded alumina slurry used in a previous experimental investigation and is modeled as a viscoplastic Bing-ham fluid with a yield stress. For different substrate speeds, the entire flow domain is analyzed and the extent and shape of yielded/unyielded regions are found. The computed free surface profiles are in close agreement with the experimental ones. Large vortices appear in the reservoir and their intensity is computed under different operating conditions. The lubrication approximation theory (LAT) is then used to deduce a new reservoir design with tapered walls avoiding recirculation. Subsequent FEM studies show the adequacy of the new design to achieve certain criteria such as elimination of vortices and an evenly distributed unyielded region. It is proposed that a combination of LAT and FEM techniques be used for design of ceramic tape casting equipment.     

The significance of flood regimes for carabid beetle and spider communities in riparian habitats—a comparison of three major rivers in Germany

River regulation and water management practices have led to alteration of the flood regimes of all large rivers in Germany. To investigate its influence on the terrestrial arthropod fauna, a comparative study was carried out on the distribution of ground beetles (Carabidae) and spiders (Araneae) at the potamal sections of three large rivers in northern Germany, the Rivers Weser, Elbe and Oder. The three rivers differ markedly in their flood dynamics, mainly owing to weirs and polder management practices, but also owing to natural conditions in their headwaters. In total, 45 sites were examined with a total capture of 46 727 carabid beetles and 38 066 adult spiders, representing 178 and 209 species, respectively. Using multivariate TWINSPAN analyses we found that the ground beetle species assemblages clearly varied according to the different flood regimes. By contrast, the spiders differentiate well between sites of different habitat structure. In particular, the river margins hosted a specialized carabid fauna, and the alluvial Quercus–Ulmus forests were habitat for some rare and endangered carabid and spider species. Whereas the fauna of the strongly regulated River Weser was impoverished regarding stenotopic hygrophilous species, the fauna of the more natural Rivers Elbe and Oder depended very much on the duration and timing of the flooding, as well as on the local micro‐topographical situation. It is concluded that low lying areas behind dykes of the Elbe, or in polders of the Oder, which become frequently inundated by river or ground water, are extremely valuable for invertebrate conservation. The data suggest that careful polder management may support suitable habitat creation for riparian species, as long as the inundation scheme corresponds to natural flood dynamics conditions. Copyright © 2002 John Wiley & Sons, Ltd.     

Kalirückstandshalde Sollstedt (Thüringen): Untersuchungen zur Ausbreitung der Haldenlösung im Rötkarst

The Sollstedt potash waste pile has been deposited without a basement layer on the Middle Bunter and Roethian. Therefore, a part of the salts dissolved by meteoric water infiltrates into the groundwater. The strongly mineralized waste pile seepage water spreads not only into the Middle Bunter but also into the Roethian, which is generally considered an aquitard, because in this area the Roethian is strongly karstic. This study demonstrates that there is a relationship between the seepage water and the strongly mineralized springs surrounding the stockpile. In particular, the strong mineralization of the Silze spring, which is situated in the supposed direction of groundwater flow, can be attributed to mixing with the seepage water. From the calculated water and salt balances, it is concluded that the major part of the seepage water which previously infiltrated in the Roethian infiltrates directly into the Middle Bunter. This suggests a preferential but locally limited permeability of the Roethian in the horizontal and vertical directions.     

Domain decomposition improvement of quark propagator estimation

Applying domain decomposition to the lattice Dirac operator and the associated quark propagator, we arrive at expressions which, with the proper insertion of random sources therein, can provide improvement to the estimation of the propagator. Schemes are presented for both open and closed (or loop) propagators. In the end, our technique for improving open contributions is similar to the “maximal variance reduction” approach of Michael and Peisa, but contains the advantage, especially for improved actions, of dealing directly with the Dirac operator. Using these improved open propagators for the Chirally Improved operator, we present preliminary results for the static-light meson spectrum. The improvement of closed propagators is modest: on some configurations there are signs of significant noise reduction of disconnected correlators; on others, the improvement amounts to a smoothening of the same correlators.     

Involvement of T cells in enhanced resistance to Klebsiella pneumoniae septicemia in mice treated with liposome-encapsulated muramyl tripeptide phosphatidylethanolamine or gamma interferon

We have previously shown that prophylactic administration of the liposome-encapsulated immunomodulating agents muramyl tripeptide phosphatidylethanolamine (MTPPE) and gamma interferon (IFN-gamma) results in strongly increased survival of mice from a normally lethal septicemia with Klebsiella pneumoniae. It was anticipated that the treatment acts on macrophages and nonspecifically augments host resistance to various infections. In the present study, we provide evidence for a key role for T cells in host defense potentiation by the liposomal immunomodulators toward K. pneumoniae septicemia. It is shown that both CD4 and CD8 cells are important in immunomodulation, most likely due to production of IFN-gamma. Depletion of circulating IFN-gamma resulted in strong reduction of the antimicrobial host defense activation. Administration of interleukin-10 resulted in decreased antimicrobial host defense activation by liposomal immunomodulators. Moreover, administration of liposomal immunomodulators was shown to induce predominantly T-helper type 1 (Th1) cell populations in the spleen. These findings indicate that immunomodulation with liposomal MTPPE and IFN-gamma favors Th1 and NK cell activation.     

An overview of clinical policies with implications for clinical practice, medical education, and research

Clinical policies, also known as practice parameters or practice guidelines, are gaining notoriety out of a desire to control escalating medical costs, lessen wide practice variations, and improve quality of care. The clinical policies are supposed to influence medical decision making by summarizing scientific data about a clinical problem in a format that is easily understood by patient and physician alike. Developing an evidence-based policy involves: a clearly defined clinical problem, a comprehensive literature review, a summary table of the data (known as an evidence table), a presentation of this data as outcome possibilities from alternative decisions (in the form of a balance sheet), and creation of clinical recommendations that incorporate both financial costs and patient preferences. Well-developed policies can be used by family physicians as guides in areas of clinical uncertainty and by medical educators as up-to-date literature syntheses for teaching critical appraisal and for outlining approaches to common problems. Explicit policy formulation also highlights the shortcomings of existing literature and can suggest more appropriate future research. The future of the clinical policy movement rests on its ability to reduce costs of care and improve patient outcomes. Explicit clinical policy formulation incurs significant development and implementation costs and the evidence on which many policies are based is lacking. Nevertheless, clinical policies in some form are likely to play an increasing role in medical care.     

Physics-based preconditioner for iterative algorithms in MoM-problems

An efficient method to solve electromagnetic scattering problems involving several metallic scatterers or bodies composed of dielectric and metallic regions is proposed. For this, the block Jacobi preconditioner is combined with the iterative transpose-free quasi-minimum residual (TFQMR) algorithm. For best performance, the blocks for the preconditioner are chosen according to individual scatterers or groups of scatterers, or according to the electric and magnetic current basis functions for dielectric/metallic scatterers.     

Locally applied antisense oligonucleotide to proliferating cell nuclear antigen inhibits intimal thickening in experimental vein grafts

This study examines the effect of antisense oligonucleotide to proliferating cell nuclear antigen (PCNA) on the formation of vein graft intimal hyperplasia in vivo, using localized administration. Twenty-four New Zealand white rabbits had a right carotid interposition bypass graft using the external jugular vein and were sacrificed on the 28th postoperative day. To determine the effect of PCNA on the development of intimal hyperplasia, 6 animals had their grafts coated with a pluronic gel containing 18 base antisense oligonucleotide to PCNA (1 mg/ml), 6 received a pluronic gel containing an 18 base nonsense oligonucleotide (1 mg/ml), and 12 animals were controls (6 with and 6 without pluronic gel). These grafts were harvested for morphology and videomorphometry. There was no change in the intimal thickness between the control and gel-treated groups. (70 +/- 4 microm versus 72 +/- 4 microm; mean +/- s.e.m.; p = ns). The presence of nonsense oligonucleotide had no further effect. Antisense PCNA produced a 26% decrease in intimal thickness to 50 +/- 4 microm in the treated vein grafts (p < 0.03) without a change in medial thickness. This study shows that a local single application of antisense oligonucleotide to PCNA will reduce the intimal hyperplasia in experimental vein grafts over 28 days.