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991.
DC Middleton 《Canadian Metallurgical Quarterly》1998,106(12):765-767
Chronic beryllium disease (CBD) is typically considered only when occupational exposure to beryllium is a certainty; however, CBD has also occurred in occupational and environmental settings where exposure was unexpected. When the etiology of a case of granulomatous pulmonary disease is not determined, sarcoidosis is the "diagnosis of exclusion." This diagnosis does not communicate much information about the patient's prognosis, the disease's etiology, or even what disease etiologies were specifically excluded. Some cases of CBD have been called sarcoidosis, allowing exposure to continue for the patient and (at times) other individuals. The granulomatous changes of sarcoidosis are thought to result from an abnormal immune response. While the etiologic agents that can initiate this response are largely unknown, the immunopathogenesis of CBD has been well described, and laboratory methods are available in a few centers that can (if used) identify beryllium hypersensitivity. The potential for exposure and disease to be widely separated in time and location makes it important for health-care and environmental health professionals to be aware of these new diagnostic methods. 相似文献
992.
A fundamental concept to initiate change in the curriculum revision process is to overcome resistance to change and the boundaries of self-interest. Curriculum change cannot occur without an "unfreezing" of faculty values and interests. The Nominal Group Technique (NGT) was used to facilitate faculty identification of areas needing change in the undergraduate nursing curriculum. The process led to the generation of numerous independent ideas in which all faculty participated. The revised curriculum which resulted from the NGT process has had full and enthusiastic support of the faculty. 相似文献
993.
AG Cutillo PH Chan DC Ailion S Watanabe KH Albertine CH Durney CB Hansen G Laicher RF Scheel AH Morris 《Canadian Metallurgical Quarterly》1998,39(2):190-197
Phenolic acids, essentially hydroxycinnamic acids and hydroxybenzoic acids, are secondary plant products and commonly found in plant derived foodstuff. The antioxidant and anticarcinogenic properties of phenolic acids could be one of the facts to explain the inverse association between fruit and vegetable intake and the incidence of coronary heart disease and cancer, respectively, as found in epidemiologic studies. Phenolic acids are rarely listed in food composition tables and there are no dietary intake data available. Consequently, a data base containing the phenolic acid content of foods (literatur data) was built and 7-d dietary protocols of 63 women and 56 men of a Bavarian subpopulation (age 19-49 years) of the German National Food Consumption Survey (NVS) were evaluated. The average phenolic acid intake of men and women is 222 mg/d within a large range. The dominating one within all the phenolic acids is clearly caffeic acid (206 mg/d); the intake of the other phenolic acids amounts to 0.2 (gentisic acid) up to 5.2 mg/d (ellagic acid). The sum of hydroxybenzoic acids and hydroxycinnamic acids amounts to 11 mg/d and 211 mg/d, respectively. Significant sex differences are found for some of the phenolic acids. Especially, the average intake of caffeic acid of women (229 mg/d) is higher than that of men (179 mg/d) caused by the high amount of coffee consumption. The age group "25-49 years" is consuming more coffee than the age group "19-24 years" and, therefore, reveals a significantly higher intake of caffeic acid. The major sources of phenolic acids are coffee with 92% of the caffeic acid intake and fruits (including fruit products and juices) with 75% of the salycilic acid and 59% of the p-coumaric acid intake. Consequently, phenolic acids are consumed in considerable amounts with food. Since antioxidant and anticarcinogenic properties of phenolic acids are already proven in in vitro as well as in animal experiments, epidemiologic studies will show whether a high phenolic acid intake goes ahead with a reduced risk for coronary heart disease or cancer in humans. 相似文献
994.
LP O'Keefe JB Levitt DC Kiper RM Shapley JA Movshon 《Canadian Metallurgical Quarterly》1998,80(2):594-609
The nocturnal, New World owl monkey (Aotus trivirgatus) has a rod-dominated retina containing only a single cone type, supporting only the most rudimentary color vision. However, it does have well-developed magnocellular (M) and parvocellular (P) retinostriate pathways and striate cortical architecture [as defined by the pattern of staining for the activity-dependent marker cytochrome oxidase (CO)] similar to that seen in diurnal primates. We recorded from single neurons in anesthetized, paralyzed owl monkeys using drifting, luminance-modulated sinusoidal gratings, comparing receptive field properties of M and P neurons in the lateral geniculate nucleus and in V1 neurons assigned to CO "blob," "edge," and "interblob" regions and across layers. Tested with achromatic stimuli, the receptive field properties of M and P neurons resembled those reported for other primates. The contrast sensitivity of P cells in the owl monkey was similar to that of P cells in the macaque, but the contrast sensitivities of M cells in the owl monkey were markedly lower than those in the macaque. We found no differences in eye dominance, orientation, or spatial frequency tuning, temporal frequency tuning, or contrast response for V1 neurons assigned to different CO compartments; we did find fewer direction-selective cells in blobs than in other compartments. We noticed laminar differences in some receptive field properties. Cells in the supragranular layers preferred higher spatial and lower temporal frequencies and had lower contrast sensitivity than did cells in the granular and infragranular layers. Our data suggest that the receptive field properties across functional compartments in V1 are quite homogeneous, inconsistent with the notion that CO blobs anatomically segregate signals from different functional "streams." 相似文献
995.
The purpose of this paper is two-fold, firstly it describes the development and modelling of an experimental test facility as a platform on which to assess the performance of Iterative Learning Control (ILC) schemes. This facility includes a non-minimum phase component. Secondly, P-Type, D-Type and phase-lead types of the algorithm have been implemented on the test-bed, results are presented for each method and their performance is compared. Although all the ILC strategies tested experience eventual divergence when applied to a non-minimum phase system, it is found that there is an optimum phase-lead ILC design that maximizes convergence and minimizes error. A general method of arriving at this phase-lead from knowledge of the plant model is described. A variety of filters have been applied and assessed in order to improve the overall performance of the algorithm. 相似文献
996.
Greg Freeman Don Batory Greg Lavender Jacob Neal Sarvela 《Software and Systems Modeling》2010,9(3):359-373
Model driven engineering (MDE) of software product lines (SPLs) merges two increasing important paradigms that synthesize
programs by transformation. MDE creates programs by transforming models, and SPLs elaborate programs by applying transformations
called features. In this paper, we present the design and implementation of a transformational model of a product line of
scalar vector graphics and JavaScript applications. We explain how we simplified our implementation by lifting selected features
and their compositions from our original product line (whose implementations were complex) to features and their compositions
of another product line (whose specifications were simple). We used operators to map higher-level features and their compositions
to their lower-level counterparts. Doing so exposed commuting relationships among feature compositions in both product lines
that helped validate our model and implementation. 相似文献
997.
Stoyer MA Velsko CA Spears BK Hicks DG Hudson GB Sangster TC Freeman CG 《The Review of scientific instruments》2012,83(2):023505
Collection of representative samples of debris following inertial confinement fusion implosions in order to diagnose implosion conditions and efficacy is a challenging endeavor because of the unique conditions within the target chamber such as unconverted laser light, intense pulse of x-rays, physical chunks of debris, and other ablative effects. We present collection of gas samples following an implosion for the first time. High collection fractions for noble gases were achieved. We also present collection of solid debris samples on flat plate collectors. Geometrical collection efficiencies for Au hohlraum material were achieved and collection of capsule debris (Be and Cu) was also observed. Asymmetric debris distributions were observed for Au and Be samples. Collection of Be capsule debris was higher for solid collectors viewing the capsule through the laser entrance hole in the hohlraum than for solid collectors viewing the capsule around the waist of the hohlraum. Collection of Au hohlraum material showed the opposite pattern: more Au debris was collected around the waist than through the laser entrance hole. The solid debris collectors were not optimized for minimal Cu backgrounds, which limited the conclusions about the symmetry of the Cu debris. The quality of the data limited conclusions on chemical fractionation effects within the burning, expanding, and then cooling plasma. 相似文献
998.
PK Manasco DM Umbach SM Muly DC Godwin A Negro-Vilar MD Culler LE Underwood 《Canadian Metallurgical Quarterly》1995,80(7):2046-2052
To investigate hormonal changes occurring in male puberty, we measured LH, FSH, testosterone, and alpha-inhibin immunoactivity in serum samples drawn every 10 min for 8 h (2100-0500 h) from each of 50 normal prepubertal and pubertal boys, aged 8.4-18.8 yr. We measured gonadotropins with ultrasensitive immunofluorometric assays, and testosterone and alpha-inhibin with RIAs. Unlike previous studies, which indexed pubertal development with Tanner stages, we used testicular volume, a more finely graduated indicator of development, to reveal patterns that were obscured when subjects were grouped by Tanner stage. The overnight mean concentration of each hormone increased with testis volume, but the rate of increase on a logarithmic scale slowed as testes grew. Log LH rose precipitously in the late prepubertal and early pubertal periods and plateaued during mid- and late puberty. Based on fitted regression curves, LH increased about 20-fold (from 0.11 IU/L) between testis volumes of 1 and 10 mL, but only an additional 1.5-fold by 30 mL. The developmental trajectory of log testosterone was like that of log LH, but rose less steeply early in puberty. From 0.14 micrograms/L at a testis volume of 1 mL, testosterone increased about 8.5-fold by 10 mL and an additional 3-fold by 30 mL. In contrast, logarithms of overnight mean FSH and alpha-inhibin concentrations rose at a more nearly constant rate throughout puberty. From 0.62 IU/L at a testis volume of 1 mL, the FSH concentration doubled by 10 mL and increased an additional 1.7-fold by 30 mL. From 270 ng/L at a testis volume of 1 mL, inhibin increased 1.5-fold by 10 mL and an additional 1.3-fold by 30 mL. Overnight pulse amplitudes exhibited developmental trajectories similar to those of the corresponding overnight mean concentrations. The number of LH and testosterone pulses during the sampling period averaged 2.2 and 2.1, respectively, at Tanner stage 1 and increased to 4.5 and 3.2, respectively, at Tanner stage 5. The number of FSH and inhibin pulses remained constant throughout puberty, averaging 3.3 and 3.5, respectively. Pairwise correlations among hormone concentrations were strong, reflecting common increasing trends through puberty; however, after accounting for developmental trends, FSH, LH, and testosterone concentrations remained correlated, whereas inhibin was uncorrelated with each of the other three hormones. Measuring gonadotropins with ultrasensitive assays and analyzing the results on a logarithmic scale as a function of testis volume made clear the dramatic hormonal changes that begin before the clinical changes of puberty. 相似文献
999.
1000.