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971.
J. Lee R. T. Haftka O. H. Griffin Jr. L. T. Watson M. D. Sensmeier 《Structural and Multidisciplinary Optimization》1994,8(2-3):93-100
The present study proposes a detection technique for delaminations in a laminated beam. The proposed technique optimizes the spatial distribution of harmonic excitation so as to magnify the difference in response between the delaminated and intact beam. The technique is evaluated by numerical simulation of two-layered aluminum beams. Effects of measurement and geometric noise are included in the analysis. A finite element model for a delaminated composite, based on a layer-wise laminated plate theory is used in conjunction with a step function to simulate delaminations 相似文献
972.
The conventional way of solving the group technology (GT) problem is to start from an assignment of parts to machines and try to find a partitioning of machine cells and part families. The similarity between parts is measured based on commonality of the machines assigned to them. However, parts are assigned to machines based on their operation requirements and the operation capabilities of machines. Similarity between parts should be based on their required operations. In this paper, the authors attempt to solve or facilitate solving the GT problem at the assignment level. An algorithm for assigning parts to machines is provided which utilizes the types of operations required by parts and applies GT principles in producing the assignment. This leads to better partitioning of machine cells and part-families. Furthermore, operation sequences required by parts in determining the similarity between parts have been considered. An algorithm to form part-families based on the operation sequence similarity coefficient has been developed. The resulting families are then used by the assignment algorithm to produce machine assignments to part-families. The use of the algorithm is demonstrated by examples. 相似文献
973.
974.
R Bucala Z Makita T Koschinsky A Cerami H Vlassara 《Canadian Metallurgical Quarterly》1993,90(14):6434-6438
To address potential mechanisms for oxidative modification of lipids in vivo, we investigated the possibility that phospholipids react directly with glucose to form advanced glycosylation end products (AGEs) that then initiate lipid oxidation. Phospholipid-linked AGEs formed readily in vitro, mimicking the absorbance, fluorescence, and immunochemical properties of AGEs that result from advanced glycosylation of proteins. Oxidation of unsaturated fatty acid residues, as assessed by reactive aldehyde formation, occurred at a rate that paralleled the rate of lipid advanced glycosylation. Aminoguanidine, an agent that prevents protein advanced glycosylation, inhibited both lipid advanced glycosylation and oxidative modification. Incubation of low density lipoprotein (LDL) with glucose produced AGE moieties that were attached to both the lipid and the apoprotein components. Oxidized LDL formed concomitantly with AGE-modified LDL. Of significance, AGE ELISA analysis of LDL specimens isolated from diabetic individuals revealed increased levels of both apoprotein- and lipid-linked AGEs when compared to specimens obtained from normal, nondiabetic controls. Circulating levels of oxidized LDL were elevated in diabetic patients and correlated significantly with lipid AGE levels. These data support the concept that AGE oxidation plays an important and perhaps primary role in initiating lipid oxidation in vivo. 相似文献
975.
An improved method for the activation of polyethylene glycol with commercially available succinimidyl carbonate is described. The activated polyethylene glycol was coupled to proteins in high yield. 相似文献
976.
K Endo K Morita Y Uchiyama K Takada A Tsujimoto T Dohi 《Canadian Metallurgical Quarterly》1993,62(3):325-328
Influences of drug-induced manipulations of central serotonergic function on lidocaine- and pentylenetetrazol (PTZ)-induced convulsions were examined in mice. Agents that suppressed serotonergic transmission increased, whereas drugs that facilitated serotonin (5-HT) function decreased the incidence of lidocaine-induced convulsions. These treatments had similar influences on the incidence of PTZ-induced convulsions. Lidocaine (10(-5)-10(-3) M) reduced the stimulation evoked [3H]5-HT release from cortical slices, followed with an increased spontaneous [3H] overflow at higher concentrations. These results may suggest that brain 5-HT neurons are causally involved as inhibitory neurons in lidocaine-induced convulsions as in the case of PTZ-induced convulsions. 相似文献
977.
978.
Behavioral, cardiovascular, and self-report measures of cognitive and affective responses to 2 interpersonal challenges were examined among 20 men with a positive (FH+) and 20 with a negative (FH–) family history of hypertension. Heart rate (HR) and blood pressure (BP) were measured throughout the laboratory session; Ss were requested to self-report positive and negative conditions, state anger, and state anxiety that occurred during interactions with a male and female confederate. Behavioral responses to interpersonal tasks were videotaped, coded, and categorized into 4 major groupings (positive verbal, positive nonverbal, negative verbal, and negative nonverbal). FH+ individuals exhibited significantly higher resting HR and systolic BP reactivity to both interactions than FH– counterparts. Analyses of behavioral responses for both interactions revealed significantly more negative verbal and nonverbal behavior and less positive nonverbal behavior among FH+ as compared with FH– Ss. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
979.
T Bakács Z Végh AH Merry RB Sim L Varga Z Kertész G Tusnády E Klein 《Canadian Metallurgical Quarterly》1993,35(3):219-228
The lysis of group AB erythrocytes by human complement was studied by different anti-A and anti-B IgM monoclonal antibodies (mabs) in a 51Cr-release assay. The concentration of membrane-bound immunoglobulin was detected by ELISA, and the amount of C1q and C3 bound to sensitized red cells was measured by using purified, 125I-labelled molecules. We have demonstrated that there is an exponential relationship between the concentration of the sensitizing IgM mabs and C1q binding to the sensitized AB cell. The efficiency of binding was related to the number of antibodies bound; thus, anti-A sensitized cells bound 3-6 times more C1q than anti-B sensitized cells did. AB cells, on the other hand, bound similar amounts of C3 whether anti-A or anti-B was present. The lytic efficiencies of the various IgM mabs during short incubation times were different, suggesting that the complement activation rates vary widely with different antibodies on the AB cell membrane. The binding of C1q to an antibody-sensitized target activates a cascade, whose components may migrate away from the sensitizing antibody; interactions between the activation processes generated by the anti-A and anti-B antibodies may thus occur. Choosing appropriate pairs of anti-A and anti-B mabs for the simultaneous sensitization of AB cells has indeed resulted in stimulation in some and inhibition in other combinations of mabs. It is suggested that stimulation is observed when the activated intermediates are produced in excess, whereas inhibition occurs when a shortage of activated intermediates prevents mutual utilization. 相似文献
980.
A 40-year-old man with epidermodysplasia verruciformis showed a decrease in peripheral blood T cells and abnormal expansion of large granular lymphocytes, accompanied by increased natural killer cell activity. Surface marker analysis of his large granular lymphocytes demonstrated that the subset, CD 57+ and CD 16+, had increased. His father, who had no skin lesions of epidermodysplasia verruciformis, displayed similar blood changes and his brother showed a decrease in T cells and a slight increase in CD 16+ natural killer cells, whereas his mother revealed only a slight decrease in T cells. Our present study indicates that epidermodysplasia verruciformis might be associated with hereditary abnormal expansion of large granular lymphocytes and a decrease in T cells. 相似文献