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131.
132.
Three-dimensional gel culture systems represent conditions that mimic the differentiated state of mesenchymal cells in vivo. We examined gel contraction, cell growth, and phenotypic modulation of rabbit arterial SMC in three-dimensional gel culture. The gel contraction rate was dependent on the collagen type; that is, the contraction by freshly isolated SMC was faster and more pronounced in type I collagen than in type III collagen. In contrast, the phenotypic modulation of SMC was independent of collagen type. The major portion of cells in both type I and III collagens with growth factors underwent transition from a contractile (G0 phase) to a synthetic phenotype (G1B phase), but this transition was clearly delayed compared with that on collagens. The cells had hardly begun DNA synthesis in either collagen type and failed to proliferate even after 10 days of culture. These results indicate that collagen type is important in gel contraction by vascular SMC, while the organization of collagen fibrils (two-dimensional vs three-dimensional) is more critical in the phenotypic transition and proliferation of these cells. However, the more specific organization of extracellular matrix than the collagen gel culture system may be necessary to maintain the contractile phenotype of SMC. 相似文献
133.
The first isolated case of agenesis of the mastoid antrum, previously only described in association with the congenital syndromes trisomy 13 and mandibulofacial dysostosis, is reported. The loss of this important surgical landmark may result in disorientation and iatrogenic trauma. The surgeon must be aware of its existence, and where it is suspected the middle fossa dura should be exposed and followed posteriorly until the lateral sinus is encountered. 相似文献
134.
A wafer-bonded floating-element shear stress microsensor withoptical position sensing by photodiodes
Padmanabhan A. Goldberg H. Breuer K.D. Schmidt M.A. 《Journal of microelectromechanical systems》1996,5(4):307-315
This paper discusses a noninvasive sensing technique for the direct measurement of low-magnitude shear stresses in laminar and turbulent air flows. The sensing scheme detects the flow-induced in-plane displacement of a microfabricated floating-element structure (500 μm×500 μm×7 μm), using integrated photodiodes. The wall-mounted floating-element sensors were fabricated using a wafer-bonding technology. The sensors were calibrated in a custom-designed laminar flow cell and subsequently shown to be able to transduce shear stresses of 0.01 Pa during tests in a low-speed wind tunnel 相似文献
135.
136.
LB Bunyard LI Katzel MJ Busby-Whitehead Z Wu AP Goldberg 《Canadian Metallurgical Quarterly》1998,68(5):1136-1142
BACKGROUND: Energy requirements for weight maintenance decrease with age. Often, this decline is not proportionately matched by reduced energy intake, resulting in weight gain. OBJECTIVE: We hypothesized that energy requirements for total daily weight maintenance in healthy, sedentary, middle-aged men would increase after regular aerobic exercise or aerobic exercise plus weight loss to levels comparable with those in middle-aged athletes. DESIGN: Weight-maintenance energy requirements were determined during weight stability (+/- 0.25 kg) in 14 lean, sedentary (LS) men; 18 obese, sedentary (OS) men; and 10 male athletes of comparable ages (x +/- SEM: 58 +/- 1 y). Studies were done at baseline and after 6 mo of aerobic exercise (LS men) or aerobic exercise plus weight loss (OS men) or 3 mo of deconditioning (athletes). RESULTS: The interventions raised maximal oxygen uptake (VO2max) by 15% in the LS men and by 13% in the OS men and decreased it by 14% in athletes (all P < 0.01), eliminating the differences among groups at baseline. Body fat was reduced significantly in LS and OS men; fat-free mass decreased in OS men. Average daily energy requirements increased by 8% in LS men and by 5% in OS men (both P < 0.01) to levels comparable with the baseline requirements of athletes and correlated with VO2max (r2 = 0.22, P < 0.0001) and fat-free mass (r2 = 0.05, P < 0.02) across the range of VO2max achieved by all subjects. CONCLUSIONS: Under free-living conditions, aerobic exercise eliminated the difference in weight-maintenance energy requirements between middle-aged sedentary and athletic men, suggesting that energy requirements of healthy, middle-aged men are modifiable by regular physical activity. 相似文献
137.
HA Israel 《Canadian Metallurgical Quarterly》1997,17(4):355-366
Temporomandibular disorders are a complex group of conditions which are common causes of orofacial pain and are frequently associated with headaches. Because a wide variety of diseases can ultimately cause symptoms that result in dysfunction of the masticatory system, it is important for the clinician to establish an accurate diagnosis and rule out any serious neurologic pathology. Serious extra-articular conditions often can simulate the nonspecific symptoms of a temporomandibular joint disorder. A careful history and clinical examination of the head, neck, and cranial nerves are important in establishing a differential diagnosis. Diagnostic imaging and consultation with specialists in several disciplines are often necessary to establish an accurate diagnosis and develop an appropriate therapeutic regimen. 相似文献
138.
CD Carroll H Patel TO Johnson T Guo M Orlowski ZM He CL Cavallaro J Guo A Oksman IY Gluzman J Connelly D Chelsky DE Goldberg RE Dolle 《Canadian Metallurgical Quarterly》1998,8(17):2315-2320
An encoded 13,020-member combinatorial library was synthesized containing a statine core. Evaluation of this library with plasmepsin II, an aspartyl protease required for hemoglobin metabolism in the malaria parasite, led to the identification of potent and selective inhibitors as well as novel structure-activity relationships. 相似文献
139.
A retrospective analysis of 89 patients who underwent jejunoileal bypass surgery for morbid obesity disclosed 33 complications that were detected radiographically. Intestinal obstruction (10.1% of patients), cholecystitis (5.6%), renal stones (4.5%), peptic ulcer (3.4%), megacolon (6.7%), and elongation of the small intestine with hypertrophy of the mucosal folds of the jejunum (6.7%) were diagnosed solely by radiographic means. 相似文献
140.
Lizards (Dipsosaurus dorsalis) were placed in a desertlike environment in which the ambient temperature (Ta) at night (1800-0600 h) was 12 degrees C and the day (0600-1800 h) Ta was between 30 and 55 degrees C depending on the location within the chamber. When dead Aeromonas hydrophila (4 X 10(9) organisms) was injected into nine lizards, an elevation in body temperature (Tb) of 2.7 degrees C was observed during the same day. On the day after bacterial injection the lizards' body temperatures averaged 41.6 degrees C, an increase of 4.2 degrees C over their control day Tb. Further investigations on the febrile response of D. dorsalis were conducted at the University of Wisconsin's Biotron, where there exists a simulated desert environment with the light intensity, temperature, and humidity closely parelleling a typical spring day in the southwestern desert of the United States (the natural habitat of Dipsosaurus). In this environment injection of dead bacteria into seven lizards led to an average febrile response of similar magnitude (Tb = 40.5 degrees C) but with a longer latency than that found at the University of Michigan. Injection of 13 lizards with live A. hydrophila (5 X 10(9) organism subcut.) in the simulated desert at Michigan led to a daytime fever averaging 2.3 degrees C (mean Tb = 40.6 degrees C) over a 5-day period. During the 6th and 7th day the lizards' body temperature returned to the normal or afebrile level. Injections of sodium salicylate along with dead A. hydrophila resulted in a dose-dependent attenuation of the febrile response. These results demonstrate that the reptilian febrile response is strikingly similar to avian and mammalian fever and suggest a common origin and perhaps function for the febrile mechanism. 相似文献