Chemical and Structural Comparison of Different Commercial Food Supplements for Silicon Uptake

Various food supplements for silicon uptake were compared in terms of their structures and chemical compositions. In particular, we analyzed the silanol group content, which can be an indicator of the uptake of the siliceous species in the human body. We analyzed the commercial products Original Silicea Balsam®, Flügge Siliceous Earth Powder, Pure Colloidal Silicon, and BioSil® by applying various methods such as FTIR, 29Si NMR, and TGA. The Si-OH group content of the samples containing pure silica was the highest for the Original Silicea Balsam followed by the Pure Colloidal Silicon. The siliceous earth powder revealed the lowest content of such groups and the densest structure. BioSil® contained a considerable concentration of organic molecules that stabilized orthosilicic acid. The study may help to understand the silicon uptake behavior of different food supplements depending on their chemical structure

Enantioselective Synthesis of the Cyclopentyl Core of the Axinellamines

Axinellamines A−D (1−4) are novel bis-guanidine alkaloids isolated from the marine sponge Axinella sp. of which Axinellamines B−D (2−4) have been shown to possess bactericidal activity against Helicobacter pylori, a bacterium implicated in pepticular and gastric cancer.1 These natural products are noteworthy for the structural complexity of the polycyclic framework incorporating fused and spirocyclic ring systems. Moreover, embedded within these structures is a stereochemically complex and densely functionalized cyclopentyl core that presents a daunting synthetic challenge. A similarly substituted cyclopentane core can be found in palau'amine 5 which critically differs from that of 1−4 in the relative stereochemical relationships of the pendant functionality.2 Palau'amine 5 has attracted considerable attention due to its potent antibiotic, immunosuppressive, and cytotoxic properties (Chart 1)

Non-additivity of decoherence rates in superconducting qubits

We show that the relaxation and decoherence rates 1/T_1 and 1/T_2 of a qubit coupled to several noise sources are in general not additive, i.e., that the total rates are not the sums of the rates due to each individual noise source. To demonstrate this, we calculate the relaxation and pure dephasing rates 1/T_1 and 1/T_\phi of a superconducting (SC) flux qubit in the Born-Markov approximation in the presence of several circuit impedances Z_i using network graph theory and determine their deviation from additivity (the mixing term). We find that there is no mixing term in 1/T_\phi and that the mixing terms in 1/T_1 and 1/T_2 can be positive or negative, leading to reduced or enhanced relaxation and decoherence times T_1 and T_2. The mixing term due to the circuit inductance L at the qubit transition frequency \omega_{01} is generally of second order in \omega_{01}L/Z_i, but of third order if all impedances Z_i are pure resistances. We calculate T_{1,2} for an example of a SC flux qubit coupled to two impedances.Comment: 5 pages, 2 figure

Epoxy Resin Nanocomposites: The Influence of Interface Modification on the Dispersion Structure—A Small-Angle-X-ray-Scattering Study

The surface functionalization of inorganic nanoparticles is an important tool for the production of homogeneous nanocomposites. The chemical adaptation of the nano-filler surface can lead to effective weak to strong interactions between the fillers and the organic matrix. Here we present a detailed systematic study of different surface-functionalized particles in combination with a SAXS method for the systematic investigation of the interface interaction in the development of epoxy nanocomposites. We investigated the effect of surface modification of spherical SiO2 nanoparticles with 9 nm and 72 nm diameter and crystalline ZrO2 nanoparticles with 22 nm diameter on the homogeneous distribution of the fillers in diethylenetriamine (DETA) cured bisphenol-F-diglycidylether epoxy resin nanocomposites. Unmodified nanoparticles were compared with surface-modified oxides having diethylene glycol monomethyl ethers (DEG), 1,2-diols, or epoxy groups attached to the surface. The influence of surface modification on dispersion quality was investigated by transmission electron microscopy (TEM) and small angle X-ray scattering (SAXS) for inorganic filler contents of 3, 5 and 10 wt%. It was shown that the dispersion quality can be optimized by varying the coupling agent end group to obtain homogeneous and transparent nanomaterials. UV/VIS measurements confirmed the transparency/translucency of the obtained materials. The relationship between particle–matrix interaction and particle–particle interaction plays a decisive role in homogeneity and is controlled by the surface groups as well as by the type, size, and morphology of the nanoparticles themselves

GESIS im Urteil der Professoren und Mitarbeiter der Soziologie und Politikwissenschaft

Acht Jahre nach der telefonischen Befragung von Soziologieprofessoren in Deutschland, Österreich und der Schweiz fand eine Wiederholungsbefragung dieser Personengruppe statt. Grundlage der Befragung war eine Adressdatei von 442 Namen, Adressen, Telefonnummern und E-Mail-Adressen von Professoren der Soziologie in Deutschland, Österreich und der Schweiz. Neben einer zentralen Produktabfrage, die die Nutzung und Zufriedenheit bzw. Nicht-Nutzung und Bekanntheit erfassen sollte, wurden weitere und für die zukünftige Arbeit der GESIS bzw. deren Positionierung wichtige Aspekte in die Befragung aufgenommen. Hierzu zählen Fragen zu Veränderungen in der wissenschaftlichen Arbeitsweise und zum Informationsverhalten über das Internet, Fragen zur Bekanntheit und Bewertung neuer GESIS-Produkte im Rahmen des Wissenstranfers und der Öffentlichkeitsarbeit, wie bspw. die neue Zeitschrift 'Methoden, Daten, Analysen (mda)' oder der 'gesis report', sowie Fragen, mit denen die Akzeptanz angedachter neuer Produkte und Dienstleistungen eingeholt werden sollte (z.B. Nutzung und Bedeutung des Social Science Citation Index). Die Bewertung des Leitbildes und des Anspruchs der GESIS rundete das inhaltliche Fragenprogramm ab. Das Internet ist für die Mehrzahl der Professoren und drei Viertel der Mitarbeiter tägliches Arbeitsmittel. Fachdatenbanken werden im Vergleich mit Suchmaschinen wie Google sehr viel seltener zum Arbeiten mit dem Internet benutzt. Ein relativ großer Anteil der Befragten greift jedoch auf beide Möglichkeiten gleichmäßig zurück. Die Bereitschaft, eigene Publikationen als Volltext ins Netz zu stellen, ist bei Fachartikeln größtenteils vorhanden, fällt aber über verschiedene Publikationsformen bis hin zum Buch gravierend ab. Die Bekanntheit von GESIS ist, gemessen über zwölf Produktgruppen, fast allumfassend. Das Angebot von GESIS wurde ebenfalls von sehr vielen bereits genutzt, mit nur geringen Ausfällen zwischen sechs und 17%. Hier zeigt sich ein deutlicher Unterschied zwischen den Disziplinen: Soziologen nutzen GESIS ausgeprägter als Politologen. Bei der Nutzung einzelner Angebote gibt es eine deutliche Rangfolge mit Publikationen sowie Literatur- und Forschungsdatenbanken an der Spitze. Die Zufriedenheit mit dem Angebot ist über alle Produktgruppen hinweg hoch, und die Unterschiede sind eher gering. Die Unbekanntheit einzelner Angebote, etwa des Fortbildungsangebots, ist ebenfalls mit der Zielgruppenbestimmung abzuwägen. Eindeutige Defizite bei der Bekanntheit - bei den Politikwissenschaftlern ganz besonders - weisen der Informationsdienst 'gesis report' und die Methodenzeitschrift 'mda' auf. (LO2

Elevated myocardial and lymphocyte GRK2 expression and activity in human heart failure.

The G protein-coupled receptor kinase-2 (GRK2 or beta-ARK1) regulates beta-adrenergic receptors (beta-ARs) in the heart, and its cardiac expression is elevated in human heart failure (HF). We sought to determine whether myocardial levels and activity of GRK2 could be monitored using white blood cells, which have been used to study cardiac beta-ARs. Moreover, we were interested in determining whether GRK2 levels in myocardium and lymphocytes may be associated with beta-AR dysfunction and HF severity.In myocardial biopsies from explanted failing human hearts, GRK activity was inversely correlated with beta-AR-mediated cAMP production (R(2)=-0.215, P<0.05, n=24). Multiple regression analysis confirmed that GRK activity participates with beta-AR density to regulate catecholamine-sensitive cAMP responses. Importantly, there was a direct correlation between myocardial and lymphocytes GRK2 activity (R(2)=0.5686, P<0.05, n=10). Lymphocyte GRK activity was assessed in HF patients with various ejection fractions (EFs) (n=33), and kinase activity was significantly higher in patients with lower EFs and was higher with increasing NYHA class (P<0.001).Myocardial GRK2 expression and activity are mirrored by lymphocyte levels of this kinase, and its elevation in HF is associated with the loss of beta-AR responsiveness and appears to increase with disease severity. Therefore, lymphocytes may provide a surrogate for monitoring cardiac GRK2 in human HF

Crystalline Carbosilane‐Based Block Copolymers: Synthesis by Anionic Polymerization and Morphology Evaluation in the Bulk State

Block copolymers (BCPs) in the bulk state are known to self-assemble into different morphologies depending on their polymer segment ratio. For polymers with amorphous and crystalline BCP segments, the crystallization process can be influenced significantly by the corresponding bulk morphology. Herein, the synthesis of the amorphous-crystalline BCP poly(dimethyl silacyclobutane)-block-poly(2vinyl pyridine), (PDMSB-b-P2VP), by living anionic polymerization is reported. Polymers with overall molar masses ranging from 17 400 g to 592 200 g mol−1 and PDMSB contents of 4.8–83.9 vol% are synthesized and characterized by size-exclusion chromatography and NMR spectroscopy. The bulk morphology of the obtained polymers is investigated by means of transmission electron microscopy and small angle X-ray scattering, revealing a plethora of self-assembled structures, providing confined and nonconfined conditions. Subsequently, the influence of the previously determined morphologies and their resulting confinement on the crystallinity and crystallization behavior of PDMSB is analyzed via differential scanning calorimetry and powder X-ray diffraction. Here, fractionated crystallization and supercooling effects are observable as well as different diffraction patterns of the PDMSB crystallites for confined and nonconfined domains

Reduced pulmonary blood flow in regions of injury 2 hours after acid aspiration in rats

Background: Aspiration-induced lung injury can decrease gas exchange and increase mortality. Acute lung injury following acid aspiration is characterized by elevated pulmonary blood flow (PBF) in damaged lung areas in the early inflammation stage. Knowledge of PBF patterns after acid aspiration is important for targeting intravenous treatments. We examined PBF in an experimental model at a later stage (2 hours after injury). Methods: Anesthetized Wistar-Unilever rats (n = 5) underwent unilateral endobronchial instillation of hydrochloric acid. The PBF distribution was compared between injured and uninjured sides and with that of untreated control animals (n = 6). Changes in lung density after injury were measured using computed tomography (CT). Regional PBF distribution was determined quantitatively in vivo 2 hours after acid instillation by measuring the concentration of [68Ga]-radiolabeled microspheres using positron emission tomography. Results: CT scans revealed increased lung density in areas of acid aspiration. Lung injury was accompanied by impaired gas exchange. Acid aspiration decreased the arterial pressure of oxygen from 157 mmHg [139;165] to 74 mmHg [67;86] at 20 minutes and tended toward restoration to 109 mmHg [69;114] at 110 minutes (P < 0.001). The PBF ratio of the middle region of the injured versus uninjured lungs of the aspiration group (0.86 [0.7;0.9], median [25%;75%]) was significantly lower than the PBF ratio in the left versus right lung of the control group (1.02 [1.0;1.05]; P = 0.016). Conclusions: The PBF pattern 2 hours after aspiration-induced lung injury showed a redistribution of PBF away from injured regions that was likely responsible for the partial recovery from hypoxemia over time. Treatments given intravenously 2 hours after acid-induced lung injury may not preferentially reach the injured lung regions, contrary to what occurs during the first hour of inflammation. Please see related article: http://dx.doi.org/10.1186/s12871-015-0014-z