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SETTING: The activity of KRM 1648 (KRM), a new benzoxazinorifamycin, and rifabutin (RBT), alone or in combination with clarithromycin (CLA), was evaluated against Mycobacterium avium complex (MAC) that multiplied in human alveolar macrophages (AM). DESIGN: AM were recovered by bronchoalveolar lavage, incubated in RPMI 1640 medium with 10% human AB serum, infected with four strains of MAC (of non-acquired immune deficiency syndrome [AIDS] origin), and then treated with each drug alone or in combination. After incubation for 7 days, colony forming units in each well were counted on 7H10 agar. RESULTS: Although concentrations between 0.2 microgram/ml and 20 micrograms/ml of both rifamycins showed clear dose-dependent activities against all MAC strains tested, only 20 micrograms/ml of each drug had modest bactericidal effect. In combination with 2.0 micrograms/ml of CLA, however, 0.2 microgram/ml of both drugs caused a bactericidal response against two of the four MAC strains examined. CONCLUSION: According to this human alveolar macrophage model of MAC infection, KRM and RBT in combination with CLA was found to be a promising candidate against human pulmonary MAC infection, and deserves clinical evaluation. 相似文献
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Technetium-99m-1,1-ethyl cysteinate dimer (ECD) has been proposed as a "chemical microsphere" for SPECT measurement of regional cerebral blood flow (rCBF). However, its distribution has not yet been compared in humans to an established rCBF measure. Therefore, we compared the uptake and distribution of ECD with rCBF measured by 133Xe SPECT in subjects with mild to moderate flow abnormalities and in normal volunteers. Blood and urine chemistries and vital signs were unchanged from pre-ECD values up to seven days postinjection. Profile plots demonstrated pattern agreement between rCBF ratios (133Xe) and ECD count density ratios. A significant correlation of rCBF ratios to ECD count density ratios was observed (r = 0.77), with a slope of 0.64 and intercept of 0.36. To explore whether or not the relationship between rCBF and ECD was dependent on absolute flow, ECD region of interest data were expressed in units of ml/min/100 g by equating global CBF (133Xe) and ECD global count density. A closer correlation (r = 0.88) was found for these data than for the count ratio data. The slope was closer to one (m = 0.83) and the intercept was closer to zero (b = 8.2). Also, a significant correlation was observed between ECD-derived rCBF and 133Xe rCBF in the lesion area (r = 0.92) for patients with well-demarcated rCBF lesions. The slope (0.80) suggested a slight underestimation of lesion flow by ECD. Finally, ECD clearance from cortical gray matter ROIs derived from high-resolution scans from 1 to 4 hr postinjection was slow (2.4%/hr). In summary, ECD is a safe and effective marker of regional cerebral perfusion. The distribution of ECD is linearly related to rCBF measured by 133Xe SPECT, although our data suggest a mild underestimation of flow at the high end of the normal range. 相似文献
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The electrochemical engineering and operation of a pilot plant for the electrodeposition of Zn-Mn alloys is described in this paper. The time-averaged current density (hence c.d.) distribution on the wire and the time evolution of the bath composition are modelled and compared with experiment. Electrodeposition experiments were performed at different c.d.s on several hundred meters of steel wire; the composition of the coatings as a function of c.d. is predicted with a simple electrochemical model, also taking into account mass transport at the wire, and compared with experiment. Structural and functional properties of the coatings were studied, some effects of drawing on the coating properties were measured. The surface morphology of Zn-Mn coatings on steel wires was studied by SEM, their crystallographic structure was investigated by XRD and their in-depth composition by AES. Corrosion resistance in neutral and alkaline solutions and corrosion effects on tensile properties of the coated steel wire were measured. 相似文献
77.
Hao Chen Roman Kuziak Sybrand van der Zwaag 《Metallurgical and Materials Transactions A》2013,44(13):5617-5621
Cyclic phase transformation experiments are performed in a series of Fe-C-xMn, Fe-C-Mn-xNi, and Fe-C-Mn-xCo alloys to study the effect of alloying elements on the length of the stagnant stage during a cyclic partial phase transformation in the austenite–ferrite two-phase region. The length of stagnant stage increases linearly with the increasing Mn or Ni concentration, while Co has no effect. It was experimentally proven that the effects of alloying elements on the length of stagnant stage are additive, and the experimental results matched the predictions of the local equilibrium model very well. 相似文献
78.
Proia L Morin S Peipoch M Romaní AM Sabater S 《The Science of the total environment》2011,409(17):3129-3137
The effects of the herbicide Diuron (DIU) and the bactericide Triclosan (TCS) were assessed on laboratory-grown stream biofilms. Four week-old biofilms were exposed in mesocosms to 48-hours of short pulses of either DIU or TCS. The direct and indirect effects of each toxicant on the biofilms, and the subsequent recovery of the biofilms, were evaluated according to structural and functional biomarkers. These parameters were analyzed immediately before exposure, immediately after exposure, and 9 and 16 days post-exposure. DIU caused an increase in diatom mortality (+ 79%), which persisted until the end of the experiment. TCS also affected diatom mortality (+ 41%), although the effect did not appear until 1 week post-exposure. TCS caused an increase in bacterial mortality (+ 45%); however, this parameter returned to normal values 1 week post-exposure. TCS compromised the cellular integrity of the green alga Spirogyra sp., whereas DIU did not. TCS also strongly inhibited phosphate uptake (− 71%), which did not return to normal values until 2 weeks post-exposure. DIU directly affected algae, but barely affected the heterotrophs, whereas TCS seriously impaired bacteria (direct effect) as well as autotrophs (indirect effect). However, the biofilms recovered their normal structure and function within only a few days to a few weeks. These findings demonstrate the capacity of biofilms to cope with periodic inputs of toxicants, but also the risks associated to repeated exposure or multi-contamination in aquatic ecosystems. 相似文献
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Dipl.-Ing. Dr. mont. Pawel Krajewski Christian Bernhard Roman Krobath Thomas Schaden Sergiu Ilie 《BHM Berg- und Hüttenm?nnische Monatshefte》2014,159(7):304-305
Continuous casting of steel free of surface cracks is still one of the major quality challenges in the whole steel production. The key roles for the phenomenon of surface cracking are played by the critical strain and the temperature-dependent material’s phenomena. The new In-Situ Characterization Bending (IMC-B) method will enable the investigation of the critical strains with respect to the cracking under the main continuous casting boundaries. This publication presents potential and interesting results of the IMC-B experiment. 相似文献