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21.
Sulfate-reducing reactive walls installed in situ in the path of acid mine drainage contaminated groundwater, present a promising passive treatment technology. However, a rigorous and methodical selection of the most appropriate reactive mixture composition still needs to be investigated. The aim of this study was the selection of the most reactive medium using a multiple factor design and the modeling of the sulfate-reduction rate. Reactivity of 17 mixtures was assessed in batch reactors (in duplicates) using a synthetic AMD. Results indicate that within 41 days, sulfate concentrations decreased from initial concentrations of 2,000-3,200 mg/l to final concentrations of <90 mg/l. Metal removal efficiencies ranged between 51-84% for Ni and 73-93% for Zn. Generated sulfate-reduction rate predictive models which had very satisfactory parameters (R2 = 0.86, F = 62.38 (p-level < 10(-13)) and R2 = 0.90. F = 62.30 (p-level < 10(-13))) identified poultry manure and two other carbon sources as the critical variables for sulfate-reduction rate. 相似文献
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The effects of age stereotyping on subjects' ratings of interviewee potential were investigated using a simulated auditory interview. Male and female participants (N?=?156) listened to a 12-min interview of a supervisory candidate applying for a temporary position in industry and then rated the interviewee's qualifications for the supervisory position. Participants gave higher overall interview ratings to a younger interviewee even though he had the same qualifications as an older interviewee. Ratings given to the older interviewee, however, were not significantly different from those given to an interviewee whose age was not designated. The findings are discussed in terms of the influence of both positive and negative age stereotypes on ratings of applicant potential. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
24.
BE Gilbert C Knight FG Alvarez C Waldrep JR Rodarte V Knight WL Eschenbacher 《Canadian Metallurgical Quarterly》1997,156(6):1789-1793
Cyclosporine A (CsA) in liposomes of dilauroylphosphatidylcholine (DLPC), containing 118 micrograms of CsA/L of aerosol with a particle size of 1.6 to 1.7 micron diameter, was inhaled by 10 nonsmoking, normal volunteers each for 45 min. Aerosol was administered through an Aerotech II nebulizer (CIS-US, Inc., Bedford, MA) mouthpiece. Eight of the 10 volunteers had tracheal irritation and intermittent coughing following exposure. FEV1 and FVC values were mildly reduced, but returned to normal in 1 h. Blood chemical and hematologic values were unchanged at any time point after as opposed to before inhalation. Nine of the 10 volunteers later inhaled DLPC only, administered through the nebulizer mouthpiece. There was no change in FEV1 or FVC values, and there was no coughing or tracheal irritation. Subsequently, five of the volunteers who had previously had respiratory reactions inhaled CsA-DLPC liposome aerosol for 45-min, but through a mouth-only face mask. There was no tracheal irritation, coughing, or changes in spirometric measures. Blood concentrations of CsA at 15 min after the 45-min inhalation with a face mask averaged 83 +/- 42 ng/ml (mean +/- SD). At 24 h after treatment, CsA was undetectable in blood of the initial 10 volunteers. These studies indicate that CsA-DLPC liposome aerosol can be safely explored as a treatment for patients with moderately severe asthma. 相似文献
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26.
In this study, rat dermal fibroblasts were used as a model system to examine the ability of ligands that are known to activate protein kinase-C to regulate the levels of the mRNAs encoding basic fibroblast growth factor (bFGF) and insulin-like growth factor-I (IGF-I), two growth factors that are thought to be important in processes such as tissue repair and regeneration and wound healing. Treatment of fibroblasts with the phorbol ester phorbol 12-myristate 13-acetate (PMA), thrombin, bradykinin, serotonin, angiotensin-II, or bombesin increased protein kinase-C activity to a similar degree. Treatment of fibroblasts with 1 microM serotonin transiently increased bFGF mRNA levels about 3-fold compared to the level in control cells maintained in serum-free medium with 0.25% BSA and decreased IGF-I mRNA levels by approximately 50% compared to the level in control cells. This is similar to the previously described changes induced by bradykinin in these cells, but different from the more marked and sustained changes induced by thrombin and PMA. In contrast, angiotensin-II and bombesin had no effect on bFGF or IGF-I mRNA levels. The effects of serotonin, bradykinin, and PMA on bFGF and IGF-I mRNA levels were abrogated by preincubation of cells in 250 nM PMA to down-regulate protein kinase-C. In contrast, the effect of thrombin on bFGF mRNA levels was only partially inhibited by down-regulation of protein kinase-C, while its effect on IGF-I mRNA levels was unaffected. The activation of signaling pathways by the different ligands was further investigated to begin to determine the mechanism for the differences in the effects of thrombin vs. serotonin and bradykinin and in the effects of these three ligands vs. angiotensin-II and bombesin. All of the ligands activated phospholipase-D to a similar degree, suggesting that activation of this enzyme was not responsible for the differential effects of the ligands. In contrast, thrombin, serotonin, and bradykinin had marked effects on the hydrolysis of phosphatidylcholine and phosphatidylinositol, whereas bombesin and angiotensin-II had a small effect on phosphatidylcholine hydrolysis and no effect on phosphatidylinositol hydrolysis.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
27.
S Sidney B Sternfeld SS Gidding DR Jacobs DE Bild A Oberman WL Haskell RS Crow JM Gardin 《Canadian Metallurgical Quarterly》1993,25(8):911-916
Symptom-limited, graded exercise treadmill testing was performed by 4,968 white and black adults, ages 18-30 yr, during the baseline examination for the Coronary Artery Risk Development in Young Adults (CARDIA) study. Compared with nonsmokers, the mean exercise test duration of smokers was 29-64 s shorter depending on race/gender group (all P < 0.001), but mean duration to heart rate 130 (beats.min-1) ranged from 20-50 s longer (P < 0.05). In each race/gender group, test duration to heart rates up to 150 was 15-35 s longer (P < 0.05) in smokers than in nonsmokers after adjustment for age, sum of skinfolds, hemoglobin, and physical activity score. The mean maximum heart rate was lower in smokers than in nonsmokers (difference ranging from 6.7 beats.min-1 in white men to 11.2 beats.min-1 lower in black women, P < 0.001), although maximum rating of perceived exertion was nearly identical in smokers and nonsmokers. Chronic smoking appears to blunt the heart rate response to exercise, so that exercise duration to submaximal heart rates is increased even though maximal performance is impaired. This may result from downloading of beta-receptors caused by smoking. Smoking status should be considered in the evaluation of physical fitness data utilizing submaximal test protocols, or else the fitness of smokers relative to nonsmokers is likely to be overestimated. 相似文献
28.
Comments on the article by S. T. Fiske et al (see record 1992-07509-001) praising the American Psychological Association's (APA's) amicus brief intended to inform the Supreme Court of current scientific thinking regarding gender stereotyping. A balanced perspective, it is argued, should include both research supporting an argument and findings that are inconsistent with that argument. The APA brief gave no indication of contradictory findings. Moreover, review of the research cited indicates that more than half of the studies do not support the argument for which they were cited. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
29.
The clinical consequences of single or multiple exposure of pregnant gilts to porcine reproductive and respiratory syndrome virus (PRRSV) at various stages of gestation were determined. Thirty-three pregnant gilts were allotted to 6 experimental groups (5 to 7 gilts/group). Gilts of groups 1 to 5 were exposed to strain NADC-8 of PRRSV at the following times: group 1, gestation day (GD) 1; group 2, GDs 1 and 90; group 3, GD 30; group 4, GDs 30 and 90; group 5, GD 90. Virus exposure was by either intrauterine (GD 1) or oronasal (GDs 30 and 90) inoculation. Gilts of group 6 were kept as nonexposed controls. Gilts were either necropsied on or about GD 111 (groups 1 to 5) or were allowed to farrow (group 6). The detection of PRRSV in serum of fetuses and piglets (within 12 hof birth) was considered evidence of transplacental infection. Transplacental infection and virus-induced death were and were not confirmed for groups 3, 4, and 5 and for groups 1, 2, and 6, respectively. Collectively, the results indicated that intrauterine exposure to PRRSV at GD 1 was without clinical effect (groups 1 and 2) and provided protection against subsequent exposure to the same strain of virus at GD 90 (group 2). The highest incidence of transplacental infection and fetal death followed a single exposure to PRRSV at GD 90 (group 5). 相似文献
30.
RD Spruell ER Ferguson JJ Clymer WV Vicente CP Murrah WL Holman 《Canadian Metallurgical Quarterly》1995,41(3):M636-M641
Intravascular perfluorochemical (PFC) emulsions together with a high oxygen (O2) tension may increase the delivery of dissolved O2 to useful levels. A severely anemic model of cardiopulmonary bypass (CPB) was used to test the hypothesis that a novel PFC emulsion (PFCE; Oxygent [Alliance Pharmaceutical Corp., San Diego, CA] 90% w/v perflubron) used at a high PO2 during bypass delivers sufficient O2 to ameliorate hypoxic myocardial contractile dysfunction. Acutely anemic dogs (N = 42; hematocrit = 15.8 +/- 0.6% [mean +/- SEM] before CPB and 10.9 +/- 0.1% during CPB) were divided into four groups. Group 1 was a control (n = 12). As CPB was initiated, groups 2 (n = 10), 3 (n = 10), and 4 (n = 10) had 1.35 g PFC.kg-1, 2.7 g PFC.kg-1, or 5.4 g PFC.kg-1 added via the venous return cannula. Pre-CPB and post-CPB cardiac function was measured by the first derivative of left ventricular pressure (dP/dtmax). The dP/dtmax on separation from CPB was: group 1, 619 +/- 96; group 2, 738 +/- 56; group 3, 782 +/- 101; and group 4, 828 +/- 100 (p < 0.05 groups 3 and 4 versus group 1). Mortality during the first hour after separation from CPB was higher in group 1 than in PFCE treated dogs; however, this trend did not attain statistical significance (p < 0.065). The PFC dose was higher in survivors than in nonsurvivors (2.6 +/- 0.4 g PFC.kg-1 versus 1.2 +/- 0.5 g PFC.kg-1; p < 0.05). A PFCE used at a high PO2 provides sufficient physically dissolved O2 to relieve myocardial hypoxic injury in a severely anemic model of CPB. Current PFCEs are effective O2 carriers. This finding suggests that they can be used as a temporary erythrocyte substitute to diminish the need for allogeneic transfusions during cardiac operations. 相似文献