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31.
Microfiltration of fermentation broths . Crossflow microfiltration is a modern process for the work-up of fermentation broths. In the case of intracellular components, the cells can be enriched by this technique prior to disintegration of the cells. Extracellular products can be separated from the cells by the microfiltration membrane, and also from solids originating from the nutrient. The approach adopted in isolation of dissolved products by crossflow microfiltration is illustrated for alkaline protease, particular attention being directed to the dependence of the flow of permeate and the retention of the membrane material, the mean pore size of the membrane, the operating conditions, the physical data of the fermentation broth, and the addition of solids, which are discussed and quantified. 相似文献
32.
M. Huber S. Bechstein B. Beckhoff F. v. Feilitzsch J. Jochum M. Krumrey A. Rüdig G. Ulm 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2004,520(1-3):234-236
The characterization of an Al-STJ-based detector with Pb absorber was performed with monochromatized synchrotron radiation. Detector response was measured in the energy range from 3 to 10 keV. A small non-linearity of the signal pulse height was detected, probably due to the escape of recombination phonons from the detector. The non-linearity can be described by a second order polynomial function. Additionally, detector signals were recorded while an X-ray beam of 50 μm diameter was directed to several locations on and near the absorber. For a well-aligned beam, detector artefacts are of at least two orders of magnitude lower intensity than the absorber events. 相似文献
33.
W Hellenbrand H Boeing BP Robra A Seidler P Vieregge P Nischan J Joerg WH Oertel E Schneider G Ulm 《Canadian Metallurgical Quarterly》1996,47(3):644-650
In a case-control study, we compared the past dietary habits of 342 Parkinson's disease (PD) patients recruited from nine German clinics with those of 342 controls from the same neighborhood or region. Data were gathered with a structured interview and a self-administered food-frequency questionnaire. Nutrient intakes were calculated from the reported food intakes through linkage with the German Federal Food Code and analyzed using multivariate conditional logistic regression to control for total energy intake, educational status, and cigarette smoking. At the macronutrient level, patients reported higher carbohydrate intake than controls after adjustment for total energy intake, smoking, and educational status (OR = 2.74, 95% confidence interval [CI]: 1.30-6.07, for the highest versus lowest quartile, p trend = 0.02). This was reflected in higher monosaccharide and disaccharide intakes at the nutrient level. There was no difference between patients and controls in protein and fat intake after adjustment for energy intake. We found an inverse association between the intakes of beta-carotene (OR = 0.67, 95% CI: 0.37-1.19, p trend = 0.06) and ascorbic acid (OR = 0.60, 95% CI: 0.33-1.09, p trend = 0.04) by patients, although only the trend for ascorbic acid intake reached statistical significance. There was no difference between groups for alpha-tocopherol intake after adjustment for energy intake. We also found that patients reported a significantly lower intake of niacin than controls (OR = 0.15, 95% CI: 0.07-0.33, p trend < 0.00005). Our results suggest that if antioxidants play a protective role in this disease, the amounts provided by diet alone are insufficient. Although the interpretation of the inverse association between niacin intake and PD is complicated by the high niacin content in coffee and alcoholic beverages, which were also inversely associated with PD in this study, the strength of this association and its biologic plausibility warrant further investigation. 相似文献
34.
WilfriedUlm DaleErnette JohnKern RalfM.Bell 《热力透平》2003,(1):48-51
本文对Niederau?emK电站汽轮机的初始运行情况展开讨论,并对已使用的最新技术进行了详细的论述。 相似文献
35.
Hans D. Schick Wolfgang E. Berdel Michael Fromm Ulrich Fink Ulrich Jehn Kurt Ulm Anneliese Reichert Hansjörg Eibl Clemens Unger Johann Rastetter 《Lipids》1987,22(11):904-910
The effects of 2-lysophosphatidylcholine (2-LPC), the alkyl lysophospholipid derivatives (ALP) 1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine (ET-18-OCH3) and 1-O-hexadecyl-sn-glycero-3-phospho-trimethyl-ammonio-hexanol, the 2-acetamide analog of platelet-activating factor (PAF) 1-O-octadecyl-2-acetamide-sn-glycero-3-phosphocholine, the thioether lysophospholipid derivative (TLP) BM 41.440 and the ether-linked lipoidal amine CP-46,665 on tritiated thymidine uptake and trypan blue dye exclusion were tested in vitro in various freshly explanted cell samples from human nonneoplastic bone marrow and human leukemias. In both assay systems, a dose range of 1–20 μg/ml of the compounds was tested after 24, 48 and 72 hr of coincubation with the cells. The trypan blue dye exclusion revealed statistically significant preferential cytotoxicity in leukemic cells for three compounds with the order of quantitative selectiveness: ET-18-OCH3>BM41.440>2-acetamide analog of PAF. CP-46,665 was the most toxic compound, but did not reveal significant differences between nonneoplastic bone marrow and leukemic cells when added in concentrations greater than 1 μg/ml. The trimethyl-ammoniohexanol compound showed only minor activity in the majority of tests, when added at concentrations <20 μg/ml. 2-LPC was rather ineffective. The tritiated thymidine uptake showed only preferential antiproliferative effects towards leukemic cells of ET-18-OCH3 and, sometimes, within the dose time frame tested of BM 41.440. All compounds tested except 2-LPC and the trimethyl-ammonio-hexanol compound were active also in this assay (inhibition of uptake>50% of the controls). Based on these results, ET-18-OCH3 and BM 41.440 are recommended for experimental bone marrow purging. 相似文献
36.
Jordi Escarré Karin SöderströmCorsin Battaglia Franz-Josef HaugChristophe Ballif 《Solar Energy Materials & Solar Cells》2011,95(3):881-886
We investigate the transfer of random nanostructures commonly used in thin film silicon solar cells onto inexpensive substrates, such as glass or flexible polyethylene sheets. Morphological and optical analyses of masters and replicas show the successful transfer of details with sizes much below 1 μm. These high-quality replicas are obtained by UV nano-imprinting, avoiding the use of PDMS as an intermediate mold, which has been identified as being responsible for the lack of resolution found in previous works. 相似文献
37.
38.
Here, we investigate the ultrastructural origins of the strength of bone, which is critical for proper physiological function. A combination of dual nanoindentation, three-dimensional elastic-plastic finite element analysis using a Mohr-Coulomb cohesive-frictional strength criterion, and angle of repose measurements was employed. Our results suggest that nanogranular friction between mineral particles is responsible for increased yield resistance in compression relative to tension and that cohesion originates from within the organic matrix itself, rather than organic-mineral bonding. 相似文献
39.
Understanding of ultrasonic wave propagation in bones is essential for further development of related techniques in clinical practice. As any other saturated porous medium, bone is characterized by different forms of longitudinal wave propagation, either undrained waves or fast and (Frenkel–Biot) slow compressional waves. We here study the wave propagation in the framework of poromicromechanics. A continuum micromechanics model allows for the prediction of the anisotropic poroelastic properties, Biot’s coefficients, and moduli, from tissue-specific composition data, on the basis of tissue-independent (“universal”) elastic properties of the elementary components of all bones. These poroelastic properties enter the governing equations for wave propagation in anisotropic porous media. They allow for the prediction of undrained, fast and slow waves, as is verified by comparison of model results with experimental findings. 相似文献
40.
Kalpana Tilekar Neha Upadhyay Prof. Franz-Josef Meyer-Almes Dr. Fulvio Loiodice Natalia Y. Anisimova Tatiana S. Spirina Darina V. Sokolova Galina B. Smirnova Dr. Jun-yong Choe Dr. Vadim S. Pokrovsky Prof. Antonio Lavecchia Prof. C S Ramaa 《ChemMedChem》2020,15(19):1813-1825
In search of novel and effective antitumor agents, pyrazoline-substituted pyrrolidine-2,5-dione hybrids were designed, synthesized and evaluated in silico, in vitro and in vivo for anticancer efficacy. All the compounds exhibited remarkable cytotoxic effects in MCF7 and HT29 cells. The excellent antiproliferative activity toward MCF7 (IC50=0.78±0.01 μM), HT29 (IC50=0.92±0.15 μM) and K562 (IC50=47.25±1.24 μM) cell lines, prompted us to further investigate the antitumor effects of the best compound S2 (1-(2-(3-(4-fluorophenyl)-5-(p-tolyl)-4,5-dihydro-1H-pyrazol-1-yl)-2-oxoethyl)pyrrolidine-2,5-dione). In cell-cycle analysis, S2 was found to disrupt the growth phases with increased cell population in G1/G0 phase and decreased cell population in G2/M phase. The excellent in vitro effects were also supported by inhibition of anti-apoptotic protein Bcl-2. In vivo tumor regression studies of S2 in HT29 xenograft nude mice, exhibited equivalent and promising tumor regression with maximum TGI, 66 % (i. p. route) and 60 % (oral route) at 50 mg kg−1 dose by both the routes, indicating oral bioavailability and antitumor efficacy. These findings advocate that hybridization of pyrazoline and pyrrolidine-2,5-dioes holds promise for the development of more potent and less toxic anticancer agents. 相似文献