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121.
S Pratt 《Canadian Metallurgical Quarterly》1990,42(12):7447-7451
122.
Weidong Xiang Waters D. Pratt T.G. Barry J. Walkenhorst B. 《Communications Magazine, IEEE》2004,42(12):88-95
A three-transmitter three-receiver orthogonal frequency-division multiplexing Bell Laboratories layered space-time testbed is set up, which achieves a peak data rate of 281.25 Mb/s and a spectral efficiency of 14.4 b/Hz/s. The transmitter of the testbed consists of three signal generators transmitting three independent OFDM signals at 25 Msamples/s synchronously. Three synchronized receiving links are used, each of which includes an RF receiver, an analog-to-digital converter, a digital downconverter, and a PowerPC processor for baseband processing. The performance and complexity of three typical BLAST detection techniques (linear detection, ordered decision feedback detection, and partial decision detection) are evaluated and compared using the data from the experiments conducted in both line-of-sight and non-line-of-sight indoor environments. 相似文献
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KE Veldkamp KP Van Kessel J Verhoef JA Van Strijp 《Canadian Metallurgical Quarterly》1997,21(5):541-551
c-fos induction was investigated as a potential component in the avian photic entrainment pathway and as a possible means of locating the central pacemaker in birds. In both quail (Coturnix coturnix japonica) and starlings (Sturnus vulgaris) exposure to 1 h of light induced Fos-lir in the visual suprachiasmatic nucleus but not in the medial suprachiasmatic nucleus. However, the degree of c-fos induction in the visual suprachiasmatic nucleus was similar at different circadian times despite the fact that the light pulses caused differential phase shifts in the locomotor rhythm. For golden hamsters the same experiment resulted in significantly different levels of Fos-lir in the suprachiasmatic nucleus, as well as different phase shifts. Starlings and hamsters were also entrained to T-cycles that caused a large daily phase shift (T = 21.5 h in starlings, T = 22.67 hours in hamsters), or no daily phase shift (T = free running period). No difference in the induced levels of Fos-lir in the visual suprachiasmatic nucleus region was observed between the two groups of starlings, but in hamsters there were significantly different levels of Fos-lir in the suprachiasmatic nucleus between the two groups. 相似文献
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The buzz about hyaluronan (HA) is real. Whether found in face cream to increase water volume loss and viscoelasticity or injected into the knee to restore the properties of synovial fluid, the impact of HA can be recognized in many disciplines from dermatology to orthopedics. HA is the most abundant polysaccharide of the extracellular matrix of connective tissues. HA can impact cell behavior in specific ways by binding cellular HA receptors, which can influence signals that facilitate cell survival, proliferation, adhesion, as well as migration. Characteristics of HA, such as its abundance in a variety of tissues and its responsiveness to chemical, mechanical and hormonal modifications, has made HA an attractive molecule for a wide range of applications. Despite being discovered over 80 years ago, its properties within the world of fascia have only recently received attention. Our fascial system penetrates and envelopes all organs, muscles, bones and nerve fibers, providing the body with a functional structure and an environment that enables all bodily systems to operate in an integrated manner. Recognized interactions between cells and their HA-rich extracellular microenvironment support the importance of studying the relationship between HA and the body’s fascial system. From fasciacytes to chronic pain, this review aims to highlight the connections between HA and fascial health. 相似文献
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KP Trevett 《Canadian Metallurgical Quarterly》1998,280(10):883-884
129.
Triploidies are pregnancies that show a 69 chromosome karyotype. This chromosomal abnormality gives rise to early abortion in most cases. Triploid pregnancies, after the first three months, become molar pregnancies (molar changes inside the placenta with identifiable embryonic structures and a preeclampsia) or non molar pregnancies (isolated intauterin growth retardation). Several possibilities concerning the origin of the additional set of chromosomes exist: dispermy (the most common), diandry and digyny. The maternal and fetal clinical manifestations of this chromosomal abnormality are very diverse, which explains the difficulty of finding and recognizing this pathology. Mac Fadden's classification does not explain all the phenotypic triploid physiopathology. Formal diagnosis of triploidy depends on the fetal karyotype. The better the maternal prognosis is, the worst the fetal prognosis is. Postnatal life expectancy is not more than a few weeks. In most cases, maternal associated complications disappear with the molar evacuation. The risk of post molar tumor is discussed. However, good management of triploidy is based on an early diagnosis, before birth if that is possible. 相似文献
130.
KP Rao 《Canadian Metallurgical Quarterly》1995,7(7):623-645
In this review, an attempt was made to summarize some of the recent developments in the application of collagen as a biomaterial and in drug delivery systems. The main applications covered include: collagen for burn/wound cover dressings; osteogenic and bone filling materials; antithrombogenic surfaces; and immobilization of therapeutic enzymes. Recently, collagen used as a carrier for drug delivery has attracted many researchers throughout the world. The use of collagen for various drug delivery systems has also been reviewed in this article. Collagen-based drug delivery systems include: injectable microspheres based on gelatin (degraded form of collagen); implantable collagen-synthetic polymer hydrogels; interpenetrating networks of collagen; and synthetic polymers collagen membranes for ophthalmic delivery. Recent efforts to use collagen-liposomal composites for controlled drug delivery, as well as collagen as controlling membranes for transdermal delivery, were also reviewed. In this review, the main emphasis was on the work done in our laboratory. 相似文献