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51.
Friedrich Kiermeier und Karl Keis 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1964,125(2):96-101
Zusammenfassung Es werden Versuche zur Ermittlung des Säuerungsverlaufes und der Labfähigkeit der Milch sekretionsgestörter Euter (Molkereianlieferungsmilch) beschrieben. Die Ergebnisse zeigen, daß bei Kannenmilch infolge der Vermischung mit Milch gesunder Kühe eine nur sehr geringe Beeinträchtigung des Säuerungsvermögens gegenüber normaler Milch von Kühen mit gesunden Eutern zu erkennen ist. Demgegenüber konnte jedoch eine direkte Beziehung zwischen dem Labgerinnungsvermögen und der Stärke der Euterentzündung nachgewiesen werden, d. h. daß sich mit steigender Intensität der Entzündung die Labgerinnungszeit der Milch verlängert.Die Arbeit ist ein Auszug aus der Dissertation vonK. Keis: Der Einfluß der Euterentzündungen auf die Qualität von Milch und Milchprodukten. TH München 1963. 相似文献
52.
Olaf Ueberschär Carolin Wagner Tim Stangner Christof Gutsche Friedrich Kremer 《Polymer》2011,52(8):1829-4032
Optical tweezers accomplished with fast position detection enable one to carry out Brownian motion analysis of single DNA-grafted (grafting density: ∼1000 molecules per particle, molecular weight: 4000 bp) colloids in media of varying NaCl concentration. By that the effective hydrodynamic radius of the colloid under study is determined and found to be strongly dependent on the conformation of the grafted DNA chains. Our results compare well both with recent measurements of the pair interaction potential between DNA-grafted colloids (Kegler et al. Phys Rev Lett 2008; 100:118302) and with microfluidic studies (Gutsche et al. Microfluid Nanofluid 2006; 2:381-386). The observed scaling of the brush height with the ion concentration is in full accord with the theoretical predictions by Pincus, Zhulina, Birshtein and Borisov. 相似文献
53.
Kristina Hoffmann Tatjana Friedrich Bernd Tieke 《Polymer Engineering and Science》2011,51(8):1497-1506
Polyelectrolyte blend films and membranes were prepared upon alternating electrostatic adsorption of polyallylamine hydrochloride (PAH) and mixtures of polystyrene sulfonate (PSS) and polyacrylic acid (PAA) in different ratio on solid supports. Infrared studies indicated that the PSS‐PAA blend composition of the films always differed from the mixture composition in the dipping solution, PSS being preferentially adsorbed. Films deposited on porous supporting membranes (polyacrylonitrile/polyethylene terephthalate) were studied on their ion permeation under diffusion dialysis conditions, and their flux and salt rejection under nanofiltration and reverse osmosis (RO) conditions. Blend membranes prepared at pH 1.7 exhibit a significantly improved anion separation and salt rejection, the ideal separation factor α(NaCl/Na2SO4) of a membrane prepared from a PSS:PAA mixture of 1:1 (w/w) being 197 ± 10 (pure PAH/PSS: 45). The NaCl and Na2SO4 rejections under RO conditions are 85 and 97% (pure PAH/PSS: 15 and 27%), respectively. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers 相似文献
54.
Olaf Ueberschär Carolin Wagner Tim Stangner Konstanze Kühne Christof Gutsche Friedrich Kremer 《Polymer》2011,52(18):4021-4032
The fluid resistance of single micrometre-sized blank and DNA-grafted polystyrene microspheres under shear flow is compared in purified water and dilute λ-DNA solutions by means of optical tweezers experiments with a high spatial (±4 nm) and temporal (±0.2 ms) resolution. The measurement results show that the drag experienced by a colloid in a dilute λ-DNA solution (molecular weight of 48,502 bp per molecule, radius of gyration of 0.5 μm) is significantly decreased if the microsphere bears a grafted DNA brush. This newly discovered drag reduction effect is studied for different parameters, comprising the molecular weight of the grafted DNA molecules (250 bp, 1000 bp and 4000 bp), the concentration of the λ-DNA solution (11, 17 and 23 μg ml?1, all being significantly smaller than the critical entanglement concentration c1), the microsphere core diameter (2 μm, 3 μm and 6 μm) as well as the flow speed of the medium (10–50 μm s?1). The maximum extent of the drag reduction is found to amount to (60 ± 20)% compared to the λ-DNA-induced contribution on the drag acting on blank colloids. We propose a theoretical explanation of this effect based on the combination of the dynamic density functional theory of Rauscher and co-workers [Rauscher M. J. Phys.: Condens. Matter 2010;22:364109] and the stagnation length theory of polymer brushes, as it was established by Kim, Lobaskin et al. [Kim et al. Macromolecules 2008;42(10):3650–3655]. In particular, the solution of the Stokes equation (i.e., the Navier–Stokes equation for creeping flow) for the studied system yields a numerical prediction that is found to be in full accord with our experimental results within measurement uncertainty. 相似文献
55.
Michael R. Schütz Andreas E. Schedl Friedrich E. Wagner Josef Breu 《Applied Clay Science》2011,54(3-4):281-286
A new, facile synthesis for Fe3 +/Mg2 + LDHs is developed and investigated. The crucial feature of the synthesis is the usage of a complexing agent (diethylenetriamine, DETA) to increase the solubility of iron phases precipitated intermediately. The influences of different synthesis parameter like DETA concentration, pH value, and temperature are investigated. The optimized synthesis route yields high aspect ratio Fe3 +/Mg2 + LDHs which are expected to be interesting filler materials for flame retardant nanocomposites. 相似文献
56.
Akylbek Sydykov Himal Luitel Argen Mamazhakypov Malgorzata Wygrecka Kabita Pradhan Oleg Pak Aleksandar Petrovic Baktybek Kojonazarov Norbert Weissmann Werner Seeger Friedrich Grimminger Hossein Ardeschir Ghofrani Djuro Kosanovic Ralph Theo Schermuly 《International journal of molecular sciences》2020,21(23)
Although the response of the right ventricle (RV) to the increased afterload is an important determinant of the patient outcome, very little is known about the underlying mechanisms. Mast cells have been implicated in the pathogenesis of left ventricular maladaptive remodeling and failure. However, the role of mast cells in RV remodeling remains unexplored. We subjected mast cell-deficient WBB6F1-KitW/W-v (KitW/KitW-v) mice and their mast cell-sufficient littermate controls (MC+/+) to pulmonary artery banding (PAB). PAB led to RV dilatation, extensive myocardial fibrosis, and RV dysfunction in MC+/+ mice. In PAB KitW/KitW-v mice, RV remodeling was characterized by minimal RV chamber dilatation and preserved RV function. We further administered to C57Bl/6J mice either placebo or cromolyn treatment starting from day 1 or 7 days after PAB surgery to test whether mast cells stabilizing drugs can prevent or reverse maladaptive RV remodeling. Both preventive and therapeutic cromolyn applications significantly attenuated RV dilatation and improved RV function. Our study establishes a previously undescribed role of mast cells in pressure overload-induced adverse RV remodeling. Mast cells may thus represent an interesting target for the development of a new therapeutic approach directed specifically at the heart. 相似文献
57.
Karolina Mazur Raminder Singh Ralf P. Friedrich Hatice Gen Harald Unterweger Kamila Saasiska Rafa Bogucki Stanisaw Kuciel Iwona Cicha 《大分子材料与工程》2020,305(9)
The composites based on polylactide (PLA) and poly (3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) with the addition of antibacterial particles: silver (Ag) and copper oxide (CuO) are characterized. Basic mechanical properties and biodegradation processes, as well as biocompatibility of materials with human cells are determined. The addition of Ag or CuO to the polymers do not significantly affect their mechanical properties, flammability, or biodegradation rate. However, several differences between the base materials are observed. PLA‐based composites have higher tensile and impact strength values, while PHBV‐based ones have a higher modulus of elasticity, as well as better mechanical properties at elevated temperatures. Concerning biocompatibility, each of the tested materials support the growth of fibroblasts over time, although large differences are observed in the initial cell attachment. The analysis of hydrolytic degradation effects on the structure of materials shows that PHBV degrades much faster than PLA. The results of this study confirm the good potential of the investigated biodegradable polymer composites with antibacterial particles for future biomedical applications. 相似文献
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60.
Ralf-Peter Franke Anne Krüger Tim Scharnweber Folker Wenzel Friedrich Jung 《International journal of molecular sciences》2014,15(9):16134-16152
Effects of radiographic contrast media (RCM) application were demonstrated in vitro and in vivo where the injection of RCM into the A. axillaris of patients with coronary artery disease was followed by a significant and RCM-dependent decrease of erythrocyte velocity in downstream skin capillaries. Another study in pigs revealed that the deceleration of erythrocytes coincided with a significant reduction of the oxygen partial pressure in the myocardium—supplied by the left coronary artery—after the administration of RCM into this artery. Further reports showed RCM dependent alterations of erythrocytes like echinocyte formation and exocytosis, sequestration of actin or band 3 and the buckling of endothelial cells coinciding with a formation of interendothelial fenestrations leading to areas devoid of endothelial cells. Key to morphological alterations of erythrocytes is the membrane cytoskeleton, which is linked to the band 3 in the erythrocyte membrane via the junctional complex. Fundamental observations regarding the cell biological and biochemical aspects of the structure and function of the cell membrane and the membrane cytoskeleton of erythrocytes have been reported. This review focuses on recent results gained, e.g., by advanced confocal laser scanning microscopy of different double-stained structural elements of the erythrocyte membrane cytoskeleton. 相似文献