Shuntchirurgie bei Hämodialysepatienten: Teil 1: Die Erstanlage

Zusammenfassung: Aufgrund der demografischen Entwicklung und der ansteigenden Prävalenz des Diabetes mellitus nimmt die Zahl dialysepflichtiger Patienten stetig zu. Bei vielen dieser Erkrankten stellt die Anlage einer autologen arterio-venösen Fistel eine echte Herausforderung dar. Erweist sie sich als unmöglich, muss der Gefäßchirurg mit alternativen Zugängen sowie den Vor- und Nachteilen von alloplastischen und heterologen Prothesen vertraut sein (Teil 1). Früh- und Spätkomplikationen wie Aneurysmen, Stenosen, Verschlüsse, Infekte und Steal-Syndrom sind in der Shuntchirurgie häufig und sollten nach heute gültigen Richtlinien behandelt werden (Teil 2

Shuntchirurgie bei Hämodialysepatienten: Teil 2: Revisionen

Zusammenfassung: Aufgrund der demografischen Entwicklung und der ansteigenden Prävalenz des Diabetes mellitus steigt die Zahl dialysepflichtiger Patienten stetig an. Bei vielen dieser Erkrankten stellt die Anlage einer autologen arterio-venösen Fistel eine echte Herausforderung dar. Im ersten Teil wurde die Thematik der Neuanlage von Hämodialysezugängen besprochen. Früh- und Spätkomplikationen von Shunts wie Stenosen, Verschlüsse, Aneurysmen, Infekte und Steal-Syndrom sind bei dieser chirurgischen Technik häufig und müssen nach heute gültigen Richtlinien behandelt werden, was in diesem 2. Teil abgehandelt wir

Temperature dependence of water cluster on functionalized graphite

Our recent experimental study of water adsorption in micro-mesoporous carbons at 263 K and 298 K show an unusual temperature dependence of adsorbed density with higher loading at 298 K at the same reduced pressure. The difference is in the filling of mesopore at 298 K and its absence at 263 K, and it was conjectured to the growth of water clusters on the functional groups in the confined space of mesopores in which the water clusters at 298 K are sufficiently large to induce the subsequent filling. Since the growth of these clusters and their coalescence is the prerequisite for filling, the filling is absent at 263 K simply because of the smaller size of the clusters, preventing them from coalescence and hence, no filling. In a quest to understand the effects of temperature on water adsorption in micro-mesoporous carbon, we used molecular dynamic simulation to reveal the mechanism of water adsorption around functional groups from 263 K to 328 K to clarify the growth of the water cluster as a function of temperature. The results clearly show that the water cluster is larger at 298 K compared to 263 K, confirming the conjecture from our previous works

GG-Strands

A $G$-strand is a map $g(t,{s}):\,\mathbb{R}\times\mathbb{R}\to G$ for a Lie group $G$ that follows from Hamilton's principle for a certain class of $G$-invariant Lagrangians. The SO(3)-strand is the $G$-strand version of the rigid body equation and it may be regarded physically as a continuous spin chain. Here, $SO(3)_K$-strand dynamics for ellipsoidal rotations is derived as an Euler-Poincar\'e system for a certain class of variations and recast as a Lie-Poisson system for coadjoint flow with the same Hamiltonian structure as for a perfect complex fluid. For a special Hamiltonian, the $SO(3)_K$-strand is mapped into a completely integrable generalization of the classical chiral model for the SO(3)-strand. Analogous results are obtained for the $Sp(2)$-strand. The $Sp(2)$-strand is the $G$-strand version of the $Sp(2)$ Bloch-Iserles ordinary differential equation, whose solutions exhibit dynamical sorting. Numerical solutions show nonlinear interactions of coherent wave-like solutions in both cases. ${\rm Diff}(\mathbb{R})$-strand equations on the diffeomorphism group $G={\rm Diff}(\mathbb{R})$ are also introduced and shown to admit solutions with singular support (e.g., peakons).Comment: 35 pages, 5 figures, 3rd version. To appear in J Nonlin Sc

Silicon Does Not Alleviate The Adverse Effects Of Drought Stress In Soybean Plants

Beneficial effects of silicon (Si) in the plants growth under conditions of drought stress have been associated with to uptake and accumulation ability of element by different species. However, the effects of Si on soybean under water stress are still incipient and inconclusive. This study investigated the effect of Si application as a way to confer greater soybean tolerance to drought stress. The experiment was carried out in 20-L pots under greenhouse conditions. Treatments were arranged in a randomized block design in a 2 × 4 factorial: two water regimes (no stress or water stress) and four Si rates (0, 50, 100 and 200 mg kg-1). Soybean plants were grown until beginning flowering (R1) growth stage with soil moisture content near at the field capacity, and then it started the differentiation of treatments under drought by the suspension of water supply. Changes in relative water content (RWC) in leaf, electrolyte leakage from cells, peroxidase activity, plant nutrition and growth were measured after 7 days of drought stress and 3 days recovery. The RWC in soybean leaves decreased with Si rates in the soil. Silicon supply in soil with average content of this element, reduced dry matter production of soybean under well-irrigated conditions and caused no effect on dry matter under drought stress. The nitrogen uptake by soybean plants is reduced with the Si application under drought stress. The results indicated that the Si application stimulated the defense mechanisms of soybean plants, but was not sufficient to mitigate the negative effects of drought stress on the RWC and dry matter production.3763941395

Chemical potential, Helmholtz free energy and entropy of argon with kinetic Monte Carlo simulation

We present a method based on kinetic Monte Carlo (kMC) to determine the chemical potential, Helmholtz free energy and entropy of a fluid within the course of a simulation. The procedure requires no recourse to auxiliary methods to determine the chemical potential, such as the implementation of a Widom scheme in Metropolis Monte Carlo simulations, as it is determined within the course of the simulation. The equation for chemical potential is proved, for the first time in the literature, to have a direct connection with inverse Widom potential theory in using real molecules rather than ghost molecules. We illustrate this new procedure by several examples, including fluid argon and adsorption of argon as a non-uniform fluid on a graphite surface and in slit pores. © 201

Efficient and precise CRISPR/Cas9-mediated MECP2 modifications in human-induced pluripotent stem cells

Patients with Rett syndrome (RTT) have severe mental and physical disabilities. The majority of RTT patients carry a heterozygous mutation in methyl-CpG binding protein 2 (MECP2), an X-linked gene encoding an epigenetic factor crucial for normal nerve cell function. No curative therapy for RTT syndrome exists, and cellular mechanisms are incompletely understood. Here, we developed a CRISPR/Cas9-mediated system that targets and corrects the disease relevant regions of the MECP2 exon 4 coding sequence. We achieved homologous recombination (HR) efficiencies of 20% to 30% in human cell lines and iPSCs. Furthermore, we successfully introduced a MECP2(R270X) mutation into the MECP2 gene in human induced pluripotent stem cells (iPSCs). Consequently, using CRISPR/Cas9, we were able to repair such mutations with high efficiency in human mutant iPSCs. In summary, we provide a new strategy for MECP2 gene targeting that can be potentially translated into gene therapy or for iPSCs-based disease modeling of RTT syndrome

Simple model of adsorption on external surface of carbon nanotubes: a new analytical approach basing on molecular simulation data

Nitrogen adsorption on carbon nanotubes is wide- ly studied because nitrogen adsorption isotherm measurement is a standard method applied for porosity characterization. A further reason is that carbon nanotubes are potential adsorbents for separation of nitrogen from oxygen in air. The study presented here describes the results of GCMC simulations of nitrogen (three site model) adsorption on single and multi walled closed nanotubes. The results obtained are described by a new adsorption isotherm model proposed in this study. The model can be treated as the tube analogue of the GAB isotherm taking into account the lateral adsorbate-adsorbate interactions. We show that the model describes the simulated data satisfactorily. Next this new approach is applied for a description of experimental data measured on different commercially available (and characterized using HRTEM) carbon nanotubes. We show that generally a quite good fit is observed and therefore it is suggested that the observed mechanism of adsorption in the studied materials is mainly determined by adsorption on tubes separated at large distances, so the tubes behave almost independently

A molecular simulation study of adsorption and desorption in closed end slit pores: Is there a hysteresis loop?

This paper reports detailed simulations of adsorption and desorption of argon in closed end slit pores with the aim of investigating the existence of hysteresis. The classical thermodynamic approach implies that there should be no hysteresis in a closed end pore because it assumes that the condensed phase is identical to a uniform bulk liquid and that the interface between the gas-like region and the dense adsorbate region is the same when the pore fills as when it empties. Our simulations show that hysteresis is possible and we support this assertion with evidence from a critical analysis of the classical equation. Our extensive results show that hysteresis can occur in closed end pores because of the continuous structuring of the adsorbed phase induced by the combined effects of the solid-fluid interaction and the fluid-fluid interaction

Water as a potential molecular probe for functional groups on carbon surfaces

A new and simple method, using water as a potential molecular probe, is proposed for the determination of the concentration of surface oxygen groups on carbon adsorbents. The procedure is based on a determination of the Henry constant between a water molecule and a functional group from the volume integration of the Boltzmann factor over the accessible space around the functional group. Three porous carbons are used in this study to test the new method: A-5, RF-100 and RF-200. The results obtained are in good agreement with those measured by Boehm titration. This new method can be applied to adsorbents containing small concentrations of oxygen groups where the Boehm titration method may give unreliable results