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821.
822.
C Wilkin 《Canadian Metallurgical Quarterly》1993,47(3):R938-R940
823.
The geo-electrical measuring technique is frequently used for restoration purposes. However, this technique as developed in geology cannot be used without adaptations. The structure that is analysed has geometrical boundaries which influence the measurements and can lead to errors in the interpretation if they are not taken into account. This is illustrated by practical and theoretical tests. In an extensive test programme other aspects of the technique are also considered, such as the influence of electrode configuration and of moisture content. 相似文献
824.
The author explains from an engineering standpoint, how some of the camcorder components work. He discusses the solid-state image sensor, the photodetector, scanning, the shutter frame rate, optics, the recording mechanism, the viewfinder, special effects, and automatic features. Motion detection, discrimination, and compensation are also covered. Recommendations as to which features are most useful are made 相似文献
825.
The use of periodic inspection methods for early detection of motor deterioration is addressed. Two alternatives to traditional procedures that are appropriate for detecting stator-winding deterioration in three-phase induction motors of the sizes commonly found in the process industries are presented. The use of an effective-negative-sequence impedance as a predictor of incipient failure is recommended 相似文献
826.
827.
Inflammation and coagulation cannot be considered as two separate processes, since there are several connecting points making them part of unique, defensive host response. The endothelium can be considered as the first link between inflammation and coagulation, since damaged endothelium during inflammation represents a surface where proteins involved in both coagulation and the development of inflammation are expressed. During inflammation, cytokines modulate the coagulation system by downregulating the expression of thrombomodulin and the activation of protein C pattern but, at the same time, they induce the expression of tissue factor, modifying, in this way, the balance between procoagulant and anticoagulant activities. At the same time, at the site of tissue injury, platelets become activated and release several mediators that modify tissue integrity. Thrombin, formed following activation of the coagulation cascade, is essential to promote haemostasis but also stimulates several cell functions, including chemotaxis and mitogenesis, which are responsible for the spreading of the lesion and the tissue repair process. Therefore, in the study of inflammation the involvement of the coagulation pathway has to be taken into account, since the interaction between coagulation and inflammation pathways is a critical issue. 相似文献
828.
J Langhorne C Cross E Seixas C Li T von der Weid 《Canadian Metallurgical Quarterly》1998,95(4):1730-1734
B cell knockout mice are unable to clear a primary erythrocytic infection of Plasmodium chabaudi chabaudi. However, the early acute infection is controlled to some extent, giving rise to a chronic relapsing parasitemia that can be reduced either by drug treatment or by adoptive transfer of B cells. Similar to mice rendered B-cell deficient by lifelong treatment with anti-mu antibodies, B cell knockout mice (muMT) retain a predominant CD4+ Th1-like response to malarial antigens throughout a primary infection. This contrasts with the response seen in control C57BL/6 mice in which the CD4+ T-cell response has switched to that characteristic of Th2 cells at the later stages of infection, manifesting efficient help for specific antibodies in vitro and interleukin 4 production. Both chloroquine and adoptive transfer of immune B cells reduced parasite load. However, the adoptive transfer of B cells resulted in a Th2 response in recipient muMT mice, as indicated by a relative increase in the precursor frequency of helper cells for antibody production. These data support the idea that B cells play a role in the regulation of CD4+ T subset responses. 相似文献
829.
830.
JL Van Laethem M Cremer MO Peny M Delhaye J Devière 《Canadian Metallurgical Quarterly》1998,43(6):747-751
Microcapsules are used for the formulation of drug controlled release and drug targeting dosage forms. Encapsulated hydrophobic drugs are often applied as their solutions in plant oils. The uptake of the oils in the complex coacervate microcapsules can be improved by the addition of surfactants. In this study, soybean, olive and peanut oils were chosen as the representatives of plant oils. The well characterized complex coacervation of gelatin and acacia has been used to produce the microcapsules. The amount of encapsulated oil has been determined gravimetrically. The encapsulation of the oils was high (75-80%). When the surfactants with HLB values from 1.8 to 6.7 were used, the amount of encapsulated oil was high (65-85%). A significant decrease of the oil content in the microcapsules was found when Tween 61 with HLB = 9.6 had been added into the mixture. No oil was found inside the microcapsules from the coacervate emulsion mixture containing Tween 81 (HLB = 10) and Tween 80 (HLB = 15), respectively. The results of the experiment confirm the dependence of hydrophobic substance encapsulation on the HLB published recently for Squalan. 相似文献