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154.
OM Elashry G Giusti RB Nadler EM McDougall RV Clayman 《Canadian Metallurgical Quarterly》1997,158(2):363-369
The choline-containing phosphoglycolipid, MfGL-II, is the major polar lipid of Mycoplasma fermentans PG18. Anti-MfGL-II antisera raised in rabbits using the purified MfGL-II as an immunogen were employed in immunogold electron microscopic and immunofluorescence studies showing that MfGL-II is uniformly distributed and exposed on the cell surface of M. fermentans cells. The specificity of the antibodies was determined by immunostaining of lipid extracts separated by thin layer chromatography. The antibodies recognize lipids specific to M. fermentans but did not cross-react with lipid extracts of M. penetrans, M. capricolum, M. gallisepticum or Acholeplasma laidlawii. As phosphocholine almost completely abolished antibody interaction with MfGL-II in an ELISA assay it is suggested that the anti-MfGL-II repertoire is composed primarily of anti-phosphocholine antibodies. The anti-MfGL-II antisera inhibit the attachment of M. fermentans to Molt-3 lymphocytes suggesting that MfGL-II plays a major role in M. fermentans-host cell interaction. 相似文献
155.
Ceftriaxone has a very high plasma protein binding (up to 98%) that is saturable and decreases with higher concentrations. This high protein binding results in high concentrations in plasma that are frequently related to the anti-infective activity. However, because only the free fraction of the drug is pharmacologically active and most of the infections are located in the tissues, it is more relevant to evaluate unbound concentrations in the interstitial space. Plasma and tissue pharmacokinetics of ceftriaxone in rats after single intravenous administration were investigated at two different concentrations (50 and 100 mg/kg). Both plasma and tissue samples were taken simultaneously from the same animal and analyzed by reversed-phase high-performance liquid chromatography. Free tissue levels in the thigh muscle were measured by microdialysis. The concentration in plasma is much higher than the free concentration in tissue. After determination of nonlinear protein binding by microdialysis and including these parameters in the pharmacokinetic model, it is possible to predict free concentrations in the interstitial space from plasma levels for any given dose. 相似文献
156.
The prognostic significance of tumor cell detection in intraoperative pleural lavage and lung tissue cultures for patients with lung cancer 总被引:1,自引:0,他引:1
J Buhr KH Bergh?user S Gonner C Kelm EA Burkhardt WM Padberg 《Canadian Metallurgical Quarterly》1997,113(4):683-690
METHODS: Three hundred forty-two patients with lung cancer and 99 patients with nonneoplastic lung diseases (control group) underwent intraoperative pleural lavage with 300 ml physiologic saline solution before (lavage I) and after resection (lavage II). RESULTS: Studies of the lavage fluid in all control patients were negative, that is, there were no false positive findings. Tumor cells were found in lavage I in 132 patients (38.6%) and also in lavage II in 99 of them. In stage I (pT1 N0, pT2 N0) lung cancer, tumor cell detection was possible in 47 patients (28.6%). The 4-year survival of patients with resected non-small-cell lung cancer was 24% (95% confidence interval, 16% to 32%) if lavage I results were positive and 52% (95% confidence interval, 45% to 59%) if lavage I results were negative (all stages, p = 0.007). For patients with stage I disease (n = 164) the 4-year survival was 35% (95% confidence interval, 18% to 52%) if lavage I results were positive (n = 47), and 69% (95% confidence interval, 60% to 78%) if lavage I results were negative (n = 117) (p = 0.037). On multivariate analysis the positive cytologic result in intraoperative pleural lavage was an additional prognostic factor for our patients. To prove how the tumor cells enter the pleural cavity, we performed tissue cultures of tumor-free parenchyma in 23 cases of lung cancer. Tumor cell detection by histology and immunohistology was possible in 16 cases (69.6%). Detection of tumor cells in pleural lavage fluid before resection proves that tumor cells have spread into the pleural cavity. CONCLUSION: The positive result in pleural lavage seems to be a prognostic predictor for patients with lung cancer. 相似文献
157.
Krishna K. Seijger G. B. F. van den Bleek C. M. Makkee M. Calis H. P. A. 《Topics in Catalysis》2004,30(1-4):115-121
Topics in Catalysis - Several zeolite-based catalysts containing Ce3+ and/or CeO2 were prepared by a variety of catalyst preparation techniques like ion exchange, solid-state ion exchange,... 相似文献
158.
Johan P. den Breejen Anne M. Frey Jia Yang Anders Holmen Matti M. van Schooneveld Frank M. F. de Groot Odile Stephan Johannes H. Bitter Krijn P. de Jong 《Topics in Catalysis》2011,54(13-15):768-777
A highly active and selective manganese oxide-promoted silica-supported cobalt catalyst for the Fischer?CTropsch reaction is reported. Co/MnO/SiO2 catalysts were prepared via impregnation of a cobalt nitrate and manganese nitrate precursor, followed by drying and calcination in an NO/He flow. The catalysts were studied with STEM?CEELS, infrared spectroscopy measurements of adsorbed CO and Steady-State Isotopic Transient Kinetic Analysis experiments. Based on those experiments, a relation between C5+-selectivity and surface-coverages of CH x -intermediates on cobalt was found. 相似文献
159.
Ali Mesbah Adrie E. M. Huesman Herman J. M. Kramer Zoltan K. Nagy Paul M. J. Van den Hof 《American Institute of Chemical Engineers》2011,57(6):1557-1569
This article presents a model‐based control approach for optimal operation of a seeded fed‐batch evaporative crystallizer. Various direct optimization strategies, namely, single shooting, multiple shooting, and simultaneous strategies, are used to examine real‐time implementation of the control approach on a semi‐industrial crystallizer. The dynamic optimizer utilizes a nonlinear moment model for on‐line computation of the optimal operating policy. An extended Luenberger‐type observer is designed to enable closed‐loop implementation of the dynamic optimizer. In addition, the observer estimates the unmeasured process variable, namely, the solute concentration, which is essential for the intended control application. The model‐based control approach aims to maximize the batch productivity, as satisfying the product quality requirements. Optimal control of crystal growth rate is the key to fulfill this objective. This is due to the close relation of the crystal growth rate to product attributes and batch productivity. The experimental results suggest that real‐time application of the control approach leads to a substantial increase, i.e., up to 30%, in the batch productivity. The reproducibility of batch runs with respect to the product crystal size distribution is achieved by thorough seeding. The simulation and experimental results indicate that the direct optimization strategies perform similarly in terms of optimal process operation. However, the single shooting strategy is computationally more expensive. © 2010 American Institute of Chemical Engineers AIChE J, 57: 1557–1569, 2011 相似文献
160.
Sung Wook Hwang Jin Kie Shim Susan EM Selke Herlinda Soto‐Valdez Laurent Matuana Maria Rubino Rafael Auras 《Polymer International》2012,61(3):418-425
Poly(L ‐lactic acid) (PLLA) films containing various concentrations of two natural antioxidants, α‐tocopherol and resveratrol, were fabricated by a melt compounding and compression molding process. The influence of the antioxidants on the optical properties such as color and UV‐visible light transmission was analyzed. The thermal, mechanical, rheological and physical properties of PLLA films with added antioxidants were assessed. PLLA films with added α‐tocopherol and resveratrol showed a yellowish brown color and the lightness was influenced by the presence of the antioxidants. The glass transition and melting temperatures were significantly reduced with the addition of antioxidants while enhanced thermal stability was observed, which could be a benefit and important for processing and production. PLLA films with added antioxidants were slightly more hydrophobic than neat PLLA. The combination effect of plasticizing and enhancement of the elastic modulus with differing concentrations of two antioxidants played a critical role in the mechanical and thermomechanical properties of PLLA films. The melt viscosity of the PLLA films with added antioxidants was substantially higher than that of neat PLLA. The higher melt viscosity and G′(ω) could be an indication of formation of entanglement between PLLA and the two antioxidants. Copyright © 2012 Society of Chemical Industry 相似文献