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991.
The cellular response to trauma and infection was studied in a murine model of posttraumatic osteomyelitis. Osteoclast response differed markedly depending on whether infection with Staphylococcus aureus accompanied the bone trauma. In animals recovering from sterile trauma, osteoclastic activity that was limited to the damaged or dead bone fragments caused rapid elimination of all recognizable dead bone within 1 week. New bone was laid down in an orderly fashion. Animals with superimposed infection had an intense polymorphonuclear leukocyte response develop. Additionally, osteoclasts behaved as acute inflammatory responders with substantial activity at the margins of the infected site and at previously uninjured tibial cortex adjacent to the infection. Despite the exuberant osteoclast response, bony fragments were not resorbed (for at least 4 weeks after the trauma), that is, sequestra developed, and new bone was laid down over morphologically dead bone and on the cortex (involucrum). When the inhibitory cytokine, interleukin 4 was given in a single dose with the bacterial inoculum, the osteoclast response was moderated with almost complete elimination of osteoclast activity at normal tibial cortex adjacent to the infected site. The limitation of osteoclastic activity did not impair the host's containment of bacterial growth. 相似文献
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SM Caparroz-Assef CA Bersani-Amado EA do Nascimento AM Kelmer-Bracht EL Ishii-Iwamoto 《Canadian Metallurgical Quarterly》1998,99(1):93-116
The effects of nimesulide on energy metabolism and the hepatic metabolic alterations produced by adjuvant-induced arthritis were investigated in the perfused rat liver an in isolated liver mitochondria. Nimesulide, at therapeutic levels (20-50 microM), produced: (1) stimulation of oxygen consumption in the perfused rat liver and in isolated mitochondria, (2) inhibition of gluconeogenesis; (3) reduction of ADP/O ratio and the respiratory control ratio and stimulation of glycogenolysis in the livers from healthy rats, but not in livers from arthritic rats. These results indicate that nimesulide acts as a mitochondrial uncoupler. The main alterations produced by adjuvant-induced arthritis were: higher rates of oxygen consumption in both perfused livers and isolated mitochondria, with no decrease in the efficiency of mitochondrial energy transduction; (2) decreased gluconeogenesis and lack of glycogenolytic response to uncouplers, but not to alpha 1-agonists. These data allow to conclude that nimesulide-induced impairment of energy metabolism should worsen the hepatic disturbances that are already associated with the adjuvant disease. 相似文献
997.
W. Yang J.P. Edwards C.R. Eastwood B.T. Dela Rue A. Renwick 《Journal of dairy science》2021,104(1):431-442
The use of precision technology is increasingly seen as an option to improve productivity, animal welfare, resource use efficiency, and workplace features on dairy farms. There is limited research related to longitudinal adoption patterns of precision dairy technologies and reasons for any patterns. The aim of this analysis was to investigate trends in technology adoption regarding both the amount (number of farms with a technology) and intensity (number of technologies per farm) of adoption. Surveys of parlor technology adoption were conducted on New Zealand dairy farms in 2008, 2013, and 2018, with 532, 500, and 500 respondents, respectively. Technologies were grouped into labor-saving (LS, such as automatic cluster removers) or data-capture (DC, such as in-line milk meters) categories. Trends were examined for farms that had only LS, only DC, or LS+DC technologies. Technology adoption increased over time; the likelihood of technology adoption in 2018 (and 2013 in parentheses) increased by 21 (22), 7 (68), and 378% (165) for LS, DC, and LS+DC technology groups, respectively, compared to 2008. Farms with LS+DC technologies also had a greater proportion of LS technologies compared to non-LS+DC farms, although this relationship declined over the 10-yr period. The use of a rotary versus herringbone parlor was estimated to be associated with 356 and 470% increase in the likelihood of adopting LS technologies and LS+DC, respectively, from 2008 to 2018. Regional differences in adoption were also found, with the likelihood of adopting DC and LS+DC technologies found to be 46 and 59% greater, respectively, in the South Island of New Zealand, compared to the base region of Waikato. The results highlight the importance of understanding spatial and temporal farm characteristics when considering future effect and adoption of precision dairy technologies. For example, the analysis indicates the occurrence of 2 trajectories to technology investment on farms, where larger farms are able to take advantage of technology opportunities, but smaller farms may be constrained by factors such as lack of economies of scale, limited capital to invest, and inability to retrofit technology into aging parlor infrastructure. 相似文献
998.
Qiu B.C. Bryce A.C. de la Rue R.M. Marsh J.H. 《Photonics Technology Letters, IEEE》1998,10(6):769-771
We report the use of a laser irradiation process, which combines irradiation by continuous wave and Q-switched pulsed Nd:YAG lasers, to promote quantum-well intermixing. Differential shifts up to 70 meV have been obtained in GaInAsP structures. Extended cavity-ridge lasers with 800-μm-long active sections and 1000-μm-long passive sections, were fabricated. The slope efficiency of the extended cavity lasers is very close to that of 800-μm-long all-active lasers, and the threshold current is 10 mA higher than for an 800-μm-long all-active device. The loss in the intermixed single-mode waveguide is 2.1 cm-1 相似文献
999.
Speckle appearing in synthetic aperture radar (sar) images is generated by coherent processing of radar signals. Basically the speckle has the nature of multiplicative noise. Recently, several methods have been proposed to remove speckle in sar images, among them, Lee’s methods, Frost’s method and Zamperoni’s method. In this paper, we propose an effective method for smoothing speckle-corrupted images. Digital processing is introduced, based on a contrast modification in a multi-resolution pyramid image representation. The contrast modification is realized by a median filter or an adaptive order filter giving a reconstructed image. For assessing this new method, we realized a comparative study with several noise-smoothing algorithms. 相似文献
1000.
Raffaele L. De La Rue R.M. Roberts J.S. Krauss T.F. 《Photonics Technology Letters, IEEE》2001,13(3):176-178
We demonstrate very compact low-threshold edge-emitting semiconductor lasers operating at a wavelength of 980 nm, in which periodic microstructure mirrors have been formed at both cavity ends by deep reactive ion etching. From a threshold analysis, we determined reflectivities of ~95% for the seven-period back reflector and ~80% for the three-period front mirror. Lasing has been achieved from 20-μm-long and 8-μm-wide devices exhibiting a current threshold of 7 mA. These are among the shortest in-plane electrically pumped lasers demonstrated so far. State-of-the-art electron beam lithography (EEL) and high-aspect ratio reactive ion etching (RIE) have been used for device fabrication 相似文献