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1.
Chris Harty 《Building Research & Information》2005,33(6):512-522
An alternative approach to understanding innovation is made using two intersecting ideas. The first is that successful innovation requires consideration of the social and organizational contexts in which it is located. The complex context of construction work is characterized by inter-organizational collaboration, a project-based approach and power distributed amongst collaborating organizations. The second is that innovations can be divided into two modes: 'bounded', where the implications of innovation are restricted within a single, coherent sphere of influence, and 'unbounded', where the effects of implementation spill over beyond this. Bounded innovations are adequately explained within the construction literature. However, less discussed are unbounded innovations, where many firms' collaboration is required for successful implementation, even though many innovations can be considered unbounded within construction's inter-organizational context. It is argued that unbounded innovations require an approach to understand and facilitate the interactions both within a range of actors and between the actors and technological artefacts. The insights from a sociology of technology approach can be applied to the multiplicity of negotiations and alignments that constitute the implementation of unbounded innovation. The utility of concepts from the sociology of technology, including 'system building' and 'heterogeneous engineering', is demonstrated by applying them to an empirical study of an unbounded innovation on a major construction project (the new terminal at Heathrow Airport, London, UK). This study suggests that 'system building' contains outcomes that are not only transformations of practices, processes and systems, but also the potential transformation of technologies themselves. 相似文献
2.
The occurrence of fungi was investigated in the gut of 200 common garden lizards (Agama agama). The most important pathogenic fungus isolated was Basidiobolus haptosporus, an aetiological agent of subcutaneous zygomycosis. It was recovered from the intestinal contents of 112 (56%) lizards. Other important fungi isolated included Aspergillus spp. in 24 (12%) lizards, Candida spp. in 12 (6%), Penicillium spp. in 12 (6%) and Fusarium spp. in 12 (6%). Mucor spp. were isolated from eight (4%) male lizards only. Agamid lizards are plentiful in rural and urban areas of Nigeria. As they live in close vicinity to man, they are likely to play an important role in the spread of disease that may be caused by these fungi and its transmission to man. None of the animals investigated that yielded fungal cultures revealed any external fungal infection. 相似文献
3.
The ability of oral lactobacilli to coaggregate with streptococci and actinomycetes was investigated. Of the 7 species of lactobacilli studied, only two were capable of coaggregation and the coaggregation was restricted to streptococci. Lactobacillus salivarius strains (2/4) coaggregated with Streptococcus salivarius, Streptococcus gordonii, Streptococcus crista and tufted Streptococcus sanguis II strains. Lactobacillus fermentum (2/3) coaggregated with S. gordonii and S. sanguis. The coaggregation between L. salivarius and S. salivarius, S. gordonii or tufted S. sanguis II strains was mediated by a protein on the surface of the lactobacilli and was not inhibited by lactose. The coaggregation between L. fermentum and the streptococci was mediated by protein on the surface of the streptococci and was inhibited by lactose. 相似文献
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ZA Varga JF Thompson JC Locke-Edmunds RN Baird JR Farndon 《Canadian Metallurgical Quarterly》1995,82(6):765-769
The Haemocell S-350 device has recently been introduced for intraoperative autotransfusion. The system uses a novel membrane filter to process shed blood. In the first part of this study a 0.2-micron pore size filter was used in a randomized trial comparing the use of autotransfusion (n = 8) with bank blood controls (n = 9) during aortic reconstruction. This part of the trial was abandoned because of unexpected non-surgical bleeding. Bank blood requirements fell from a median of 3.0 (range 0.0-9.0) units to 1.5 (range 0.0-7.0) units when autotransfusion was used, but these patients had a greater perioperative blood loss (1791 (range 932-3104) versus 1140 (range 440-3840) ml). There was evidence of postoperative heparin excess with an activated partial thromboplastin time ratio of 1.3 (range 0.9-3.0) versus 1.0 (range 1.0-1.2) in controls and an activated clotting time of 206 (range 143-280) versus 137 (range 107-142) s. This was confirmed by raised plasma heparin levels and a prolonged thrombin time normalized by protamine. To improve performance a 0.6-micron pore size filter was studied in ten patients. Filtration efficiency doubled from 19 to 38 per cent. Electron micrographs demonstrated better filter clearance, but 44 per cent of the original concentration of heparin remained in the reinfusate. The S-350 device may be an attractive alternative to centrifugation for intraoperative autotransfusion but, until efficiency is improved, it should only be used for cardiovascular surgery when excess heparin can be reversed with protamine. 相似文献
8.
Urinary protein and calcium excretion were assessed in 77 patients with the hepatic glycogen storage diseases (GSD): 30 with GSD-I (median age 12.4 years, range 3.2-32.9 years), 25 with GSD-III (median age 10.5 years, range 4.2-31.3 years) and 22 with GSD-IX (median age 11.8 years, range 1.2-35.4 years). Inulin (Cinulin) and para-aminohippuric acid (CPAH) clearances were also measured in 33 of these patients. Those with GSD-I had significantly greater albumin (F = 15.07, P < 0.001), retinol-binding protein (RBP) (F = 14.66, P < 0.001), N-acetyl-beta-D-glucosaminidase (NAG) (F = 9.41, P < 0.001) and calcium (F = 7.41, P = 0.001) excretion than those with GSD-III and GSD-IX. GSD-I patients (n = 18) also had significantly higher Cinulin (F = 5.57, P = 0.009), but CPAH did not differ (F = 0.77, NS). Renal function was normal in GSD-III and GSD-IX patients. In GSD-I, Cinulin (r = -0.51, P = 0.03) and NAG excretion (r = -0.40, P = 0.03) were inversely correlated with age, whereas albumin excretion was positively correlated with age (r = +0.41, P = 0.03). RBP and calcium excretion were generally high throughout all age groups. Hyperfiltration in GSD-I is associated with renal tubular proteinuria that occurs before the onset of significant albuminuria. Deficiency of glucose-6-phosphatase within the proximal renal tubule may primarily cause tubular dysfunction, glomerular hyperfiltration being a secondary phenomenon. 相似文献
9.
The redistribution of spin-labeled phospholipid analogs across the plasma membrane of HepG2 cells, either in suspension or grown as monolayers, was investigated. After incorporation into the outer membrane leaflet spin-labeled aminophospholipids phosphatidylserine (PS) and phosphatidylethanolamine (PE) moved rapidly to the inner monolayer, whereas the analog of phosphatidylcholine (PC) disappeared more slowly from the outer leaflet. The fast, inward movement of the aminophospholipids was abolished after adenosine triphosphate (ATP)-depletion of cells, suggesting the presence of an aminophospholipid translocase in the plasma membrane of these cells. Compared with human red blood cells, the activity of the aminophospholipid translocase is two orders of magnitude higher in HepG2 cells. From these data, a transverse phospholipid asymmetry can be inferred with the aminophospholipids mainly concentrated on the inner monolayer and the choline-containing phospholipids on the outer leaflet. The relevance of the enrichment of PC in the outer membrane leaflet for the formation and composition of the bile is discussed. 相似文献
10.
The association of congenital heart block (CHB) with maternal autoantibodies to the Ro and La ribonucleoprotein antigens may be due to cross-reactions between maternal anti-La antibodies and fetal cardiac specific antigens. One of the major components of cardiac myocytes, laminin, is accessible for binding by maternal autoantibodies and we have previously reported cross-reactivity of mouse laminin with anti-La antibodies affinity purified from the sera of patients with primary Sj?gren's syndrome. Affinity purified anti-La antibodies from ten women who had at some time given birth to a child with CHB were examined for cross-reactivity with human placental laminin, which shares structural similarities with cardiac laminin. All ten anti-La antibodies bound to the surface of cryosections of normal full term placental trophoblasts. Binding could be inhibited by pre-incubation of antibodies with either La or placental laminin. Eight anti-La antibodies also reacted with placental laminin by ELISA and La inhibited up to 82% of binding to laminin while laminin inhibited up to 85% of binding to La in a dose dependent manner. Eight anti-La antibodies also bound to the surface of fetal cardiac myocytes at 10.3 weeks of gestation and five showed lower levels of reactivity with the surface of fetal cardiac myocytes at 16.5 weeks of gestation. None showed any surface staining of normal adult heart. These data confirm the cross-reactivity of anti-La antibodies with laminin and may support a placental role in preventing the majority of potentially pathogenic antibodies from reaching the fetal circulation. 相似文献