Regeneration of Carbonyl Compounds by Oxidative Cleavage of Hydrazones with Zr(O‐t‐Bu)4/tert‐Butyl Hydroperoxide

A catalytic method with Zr(O‐t‐Bu)4 as the catalyst and tert‐butyl hydroperoxide as the oxidant is described to cleave phenylhydrazones 6—9 , 14—16 to the parent carbonyl compounds under mild and neutral oxidative conditions.     

Identifiability Analysis of an In Vivo Receptor-Binding Radiopharmacokinetic System

A five-state, nonlinear model describing the pharmacokinetics of a receptor-binding radiopharmaceutical is presented. Local parameter identifiability analysis was performed preexperimentally to investigate the chemical and observational conditions required for adequate estimates of hepatic blood flow, receptor-ligand affinity, and receptor population. The ability to estimate the above parameters from externally observed kinetic data depended upon receptor-ligand affinity, the molar dose of the radiopharmaceutical, the number and coupling of the observers, and independent knowledge of the coupling coefficients or ligand-receptor affinity.     

Intraoperative and postoperative autologous transfusion in orthopedic surgery

Information was collected retrospectively on three comparable groups, 25 patients in each, who had been operated on for thoracic scoliosis. Group 1 received homologous transfusions only. Group 2 and group 3 were transfused postoperatively with drained whole blood (Solcotrans orthopaedics). Group 3 received in addition peroperatively washed packed red blood cells (Haemolite 2 Cell Saver) recirculated. The need for homologous transfusions was reduced from 119 units to 23 patients in group 1, to 36 units to 14 patients in group 2 and 34 units to 13 patients in group 3. Three of the first 15 patients in group 2 experienced chills and fever reactions in connection with the autologous transfusion. No reactions were seen after infusion when we scrapped the last 50 to 100 ml of drained blood.     

Natural graphite filled polyolefins — electrical and electrochemical behavior

Composite materials with 80 wt.-% natural graphite and 20 wt.-% polyolefins have been characterized for their application as positive electrodes in batteries. With respect to graphite, resistivity is enhanced by a factor of 10⁴ (ρ = 1–10 Ωcm), and the anisotropy factor is lowered to 10. A thin polymer film barrier and/or a thin bilayer of graphite surface groups between the graphite flakes, crossed by electron tunneling, is responsible for this and for a pronounced field effect of resistivity. The presence of a polymer binder is also indicated by a formation effect in the course of the first anion intercalation cycles performed by electrochemical experiments. Long term cycling of a model cell reveals a strong influence of the mechanical properties of the polyolefin binders. Those with high tensile strength lead to a much poorer cycle life than those with low tensile strength, where cycle numbers up to 5000 (one hour charge) have been obtained. The latter material has an improved compatibility to the periodical volume alterations in the course of electrochemical cycling.     

Praxis und Wissen – Aus der Industrie – Neues von der Montanuniversität – Personalnachrichten – Neues von der ASMET – Tagungsankündigungen – Hinweise auf Neuerscheinungen

BHM Verbandsnachrichten

Praxis und Wissen – Aus der Industrie – Neues von der Montanuniversit?t – Personalnachrichten – Neues von der ASMET – Tagungsankündigungen – Hinweise auf Neuerscheinungen     

Generation and Characterization of a CRISPR/Cas9-Mediated SNAP29 Knockout in Human Fibroblasts

Loss-of-function mutations in the synaptosomal-associated protein 29 (SNAP29) lead to the rare autosomal recessive neurocutaneous cerebral dysgenesis, neuropathy, ichthyosis, and keratoderma (CEDNIK) syndrome. SNAP29 is a soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein. So far, it has been shown to be involved in membrane fusion, epidermal differentiation, formation of primary cilia, and autophagy. Recently, we reported the successful generation of two mouse models for the human CEDNIK syndrome. The aim of this investigation was the generation of a CRISPR/Cas9-mediated SNAP29 knockout (KO) in an immortalized human cell line to further investigate the role of SNAP29 in cellular homeostasis and signaling in humans independently of animal models. Comparison of different methods of delivery for CRISPR/Cas9 plasmids into the cell revealed that lentiviral transduction is more efficient than transfection methods. Here, we reported to the best of our knowledge the first successful generation of a CRISPR/Cas9-mediated SNAP29 KO in immortalized human MRC5Vi fibroblasts (c.169_196delinsTTCGT) via lentiviral transduction.     

Scattering from composite materials: a first-order model

The nonspecular electromagnetic scattering from finite composite laminates is investigated. The composite material is modeled as planar lamina composed of undirectional collimated fibers with regular spacings between the elements. The fibers, perfectly or partially conductive, are assumed to be embedded in a resin matrix translucent to electromagnetic radiation. For the partially conductive case, the Schelkunoff Ansatz is used. The case of two-plied laminates with skewed fiber orientation is discussed. The mathematical formulation is based on the electric-field integral equation solved with an entire-domain Galerkin expansion. Results are obtained for laminates with both finite and infinite numbers of elements. For the latter, the Floquet-Galerkin solution for periodic structures is used. The effect of truncation of the panels is discussed for arbitrary angles of illumination. It is shown that in many cases implementation of the Floquet-Galerkin solution using diagonal system matrices yields accurate results for the nonspecular cross sections of the laminates. The theoretical results are confirmed by experimental data     

Goodness-of-fit and local identifiability of a receptor-bindingradio-pharmacokinetic system

A four-state nonlinear model describing a radiopharmacokinetic system for a hepatic receptor-binding radiopharmaceutical, [99mTc]-galactosyl-neoglycoalbumin (TcNGA), was tested for goodness-of-fit and local identifiability using scanning data from nine healthy subjects and seven patients with severe liver disease. Based on standard deviations of liver and heart imaging data at equilibria as a measure of observational error, the reduced chi-square ranged from 0.5 to 2.6. Values above 1.2 occurred when the subject moved during the 30 min study. Relative standard errors for each parameter were: TcNGA-receptor forward binding rate constant kb, 13-54%; extra-hepatic plasma volume Ve, 0.8-15.0%; hepatic plasma volume Vh, 0.2-6.5%; hepatic plasma flow F, 54----greater than 1000%; and receptor concentration [R]o, 0.3-13%. The highest standard errors occurred when the amount of TcNGA injected exceeded the total amount of receptor. Therefore, when TcNGA functional imaging was performed without excess patient motion and receptor saturation, the kinetic model provided data fits of low systematic error and yielded high precision estimates of receptor concentration and forward binding rate constant. In summary, optimal performance of the kinetic model occurred when the amount of injected TcNGA resulted in the nonlinear operation of the pharmacokinetic system.     

Root function solutions in a nucleation theory considering small cluster mobility

It is shown that discrepancies between current nucleation theory and experimental results for incomplete condensation can be surmounted if dimers and trimers are assumed to be highly mobile on the substrate surface so that most of them are captured by larger clusters. This new conception of nucleation kinetics can be described by a system of rate equations for which approximate analytical solutions are given. A peculiar feature of these solutions is the dependence of the nucleus density on a root of the deposition time. The results are compared with experimental data for gold on NaCl; in spite of some open questions the agreement is fairly good.