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排序方式: 共有1806条查询结果,搜索用时 15 毫秒
1.
We examine use of environmental information systems by ASG AB (hereafter ASG), an international logistics and transport firm headquartered in Stockholm, Sweden, as a case study to illustrate the role of information systems in life-cycle-oriented environmental management. This case provides an example of how a firm can use interorganizational information systems (IOISs) to move toward environmentally sustainable business practices. Through the use of IOISs, ASG has been able to improve its environmental performance and that of its suppliers. Further, this improved environmental performance has been a competitive advantage for ASG and enabled it to attract new business. As such, ASG's experiences illustrate how aggressive practices move environmental management beyond compliance and cost control, at which many firms have been successful, to revenue generation. The case also shows how environmentally sustainable business practices can be integrated into a firm's strategy. In addition to illustrating how ASG has used IOISs to improve environmental performance, we compare their use of environmental ISs with the expected evolution of environmental ISs presented in the Shaft and colleagues (1997) framework. Although some of ASG's experiences verify the expected progression of these types of systems, some developments are not as expected. These differences have implications for the framework. 相似文献
2.
Magnus Bundgaard 《Cell and tissue research》1987,249(2):359-365
Summary The organization of vesicular profiles in the endothelium of cerebral capillaries of the hagfish, Myxine glutinosa, has been reinvestigated. Judged from random thin sections the endothelial cells contain numerous vesicles and tubules, in contrast to brain endothelia of most other vertebrates. However, three-dimensional reconstructions based on ultrathin serial sections (thickness 18 nm) showed that the profiles represent a system of irregular tubular invaginations of the cell membrane, comparable to the vesicular invaginations demonstrated in extracerebral capillary endothelia of frogs and rats. In addition, smooth-surfaced cisternae were present in close relation to the invaginations. The function of endothelial invaginations is unknown. They do not transport macromolecules, because the blood-brain barrier is practically impermeable to proteins. However, since the system of the invaginations and smooth-surfaced cisternae is structurally similar to the system of caveolae and sarcoplasmic reticulum in smooth muscle cells, a common function seems likely. It is proposed that endothelial invaginations and smooth-surfaced cisternae are involved in regulation of cytosolic Ca++-concentration. 相似文献
3.
Magnus Westgren Anders Selbing Magnus Stangenberg 《BMJ (Clinical research ed.)》1988,296(6626):885-886
Six patients with pregnancies of 19-31 weeks'' duration showing evidence of erythroblastosis fetalis were treated with 25 fetal intracardiac blood transfusions. Complications related to the procedure occurred on five occasions in three patients. In two of the six patients the fetus died, but it was unlikely that death was related to the intracardiac transfusions.Fetal intracardiac blood transfusion may result in potentially severe complications but offers an alternative when transfusion cannot be performed into the umbilical cord. 相似文献
4.
Hans-Peter Hohn C. Richard Parker Jr. Larry R. Boots Hans-Werner Denker Magnus Höök 《Differentiation; research in biological diversity》1992,51(1):61-71
Abstract. During spontaneous or chemically induced differentiation human choriocarcinoma cells express typical characteristics of the normal differentiating trophoblast: 1) increased production of peptide and steroid hormones (chorionic gonadotropin, placental lactogen, estrogens, progesterone); 2) increased activity of cellular alkaline phosphatase; 3) morphological transition from cytotrophoblast to syncytiotrophoblast-like cells; and 4) arrested cell proliferation. Since the extracellular matrix is known to control gene expression we have examined the effects of different substrates composed of matrix macromolecules on the differentiation of BeWo choriocarcinoma cells. Matrices tested were; fibronectin, laminin, collagens type I and type IV, the basement membrane-like complex matrix Matrigel, and a complex matrix extracted from human term placenta. Irrespective of the type of molecule(s), it was consistently found that, whenever the matrix molecules were presented as threedimensional structures (as opposed to protein coatings on tissue culture plastic) the response of affected differentiation markers monitored was highly pronounced. Morphology was changed from monolayers to rounded colonies, cell proliferation was reduced, and the secretion of chorionic gonadotropin was increased up to tenfold. Heterogeneous effects were observed on progesterone secretion and on the activity of cellular alkaline phosphatase. Cell adhesion to matrix molecules, however, did not depend on the structure of the matrix. This study demonstrates that gene expression in these tumor cells can be modified by extracellular matrix and highlights that not only the presence of effector molecules in the matrix but also the three-dimensional structure of the matrix is important for the induction of differentiation. 相似文献
5.
Magnus Abrahamson Sif Jonsdottir Isleifur Olafsson Olafur Jensson Anders Grubb 《Human genetics》1992,89(4):377-380
Summary Hereditary cystatin C amyloid angiopathy (HCCAA) is a dominantly inherited disease characterized by amyloidosis, dementia and fatal cerebral hemorrhage of young adults. A method for rapid and simple diagnosis of HCCAA is described. It is based upon oligonucleotide-directed enzymatic amplification of a 275-bp genomic DNA segment containing exon 2 of the cystatin C gene from a blood sample, followed by digestion of the amplification product with AluI. Loss of an AluI recognition site in the amplified DNA segment from HCCAA patients results in a deviating band-pattern at agarose gel electrophoresis, compared with that obtained from normal subjects or unaffected HCCAA family members. In a population of 9 patients with manifest HCCAA, 14 patients with other causes of brain hemorrhage and 16 healthy individuals, the diagnostic procedure displayed a sensitivity and specificity for HCCAA of 100%. Amplified DNA segments from 4 HCCAA patients of four different families were analyzed by nucleotide sequencing; the HCCAA-causing mutation in all families was found to be a single TA substitution in the codon for amino acid residue 68 of cystatin C. 相似文献
6.
Catharina Larsson Günther Weber Eva Kvanta Kathy Lewis Marie Janson Carol Jones Tom Glaser Glen Evans Magnus Nordenskjöld 《Human genetics》1992,89(2):187-193
Summary Multiple endocrine neoplasia type 1 (MEN1) is characterized by neoplasia of the parathyroids, the pancreas, and the pituitary. Tumorigenesis involves unmasking of a recessive mutation at the MEN1 locus, which has been mapped to the centromeric part of chromosomal region 11q. In order to localize the MEN1 gene further and to make its isolation possible, a number of new markers were isolated. Two radiation-reduced somatic cell hybrids were identified that only contained markers close to and flanking the MEN1 region. DNA from these hybrids was used for the construction of a cosmid library, and clones containing human inserts were isolated. In addition, cosmid clones were isolated for locus expansion of 7 other markers that were mapped to the 11q12–13.2 region. The 33 newly isolated clones together with 25 previously published markers from this region were analyzed in a panel of radiation-reduced somatic cell hybrids. From the hybridization pattern, the region was divided into 11 parts. New restriction fragment length polymorphisms were identified in 7 of the newly isolated cosmid clones and in one plasmid. These were then used to sublocalize meiotic cross-overs more precisely in two MEN1 families, thus refining the mapping of the disease gene. 相似文献
7.
Summary A monoclonal mouse IgG2b antibody 19F8, directed towards a determinant on the retroviral transmembranous molecule p15E, binds selectively to certain rat tumours, including all tested yolk sac tumours, one rat colon carcinoma, one spontaneous kidney carcinoma and an adenovirus-type-9-induced rat breast tumour, as tested by antibody-dependent cellular cytotoxicity (ADCC) and immunohistochemistry. Groups of rats receiving yolk sac tumour F56 isografts intraperitoneally (i.p.) or subperitoneally (s.p.) were treated with this monoclonal antibody (mAb), 19F8, inoculated twice a week in doses of 100 µg. Parallel control groups received analogous inoculations of an isotype-matched monoclonal antibody. A significant growth inhibitory effect was observed with 19F8. In 5/10 rats isografted i.p., tumour outgrowth was completely inhibited and in the other 5 rats the outgrowth was delayed compared to the 10 rats in the control group, which all developed tumours. All rats of the control group developed large volumes of ascites, whereas the 5 rats in the therapy group with eventual tumour outgrowth had little or no ascites. In two experiments with rats carrying subperitoneal isografts and treated with the 19F8 mAb, tumour grew out in 4/5 and 5/10 rats, though growth was delayed compared to the control groups, in which 5/5 and 9/9 rats developed tumours. The tumours grew significantly more slowly in the therapy groups compared to the controls. All rats that developed tumours in the therapy groups showed an anti-idiotypic response against mAb 19F8. The single tumour-free rat in the first experiment and 1/5 tumour-free rats in the other showed no such response. The draining lymph node cells from the tumour-free animals showed a specific proliferative response to yolk sac tumour F56 cells in a mixed lymphocyte tumour cell culture (MLTC), and the MLTC-induced cells were cytotoxic to F56 but not to the natural-killer-sensitive rat T cell lymphoma G1—Tc1. The cytotoxic cell population was more than 90% CD4+. It is concluded that the two test systems for identification of the epitope of p15E detected by mAb 19F8 correlated well in detection of the epitope in the cells (immunohistochemistry) and at the cell surface (ADCC). It is also concluded that mAb 19F8 has a growth-inhibitory effect on yolk sac tumour F56 and that, as a result of the treatment, T cells with specificity for F56 are appearing in draining lymph nodes of tumour-free animals. 相似文献
8.
Magnus Appelberg 《Hydrobiologia》1985,121(1):19-25
During exposure to soft water, acidified to pH 4.0, the haemolymph concentrations of Na+, K+, and Cl– decreased whereas the Ca2+ concentration fluctuated in Astacus astacus. The haemocyte content of K+ decreased from 9% to 2% of the total haemolymph K+ content after exposure to pH 3.7 for 3 days. Within 14 days, 250 µg Al3+ l–1, as Al2(SO4)3 at pH 5.0, reduced the haemolymph Na+ content in Astacus astacus and Pacifastacus leniusculus, however, the effects were less pronounced than earlier reported for fish. Disturbed ion regulation, mainly depending on low pH, is thought to contribute to the absence of these species in acid waters. 相似文献
9.
The histones H3 and H2a from calf thymus are homologous to the repressor and cro repressor proteins of bacteriophage lambda in a 22-residue segment that has been implicated by mutational and model-building studies in DNA binding. In the lambda proteins this segment is folded into a helix-turn-helix unit of supersecondary structure, and we propose that the homologous regions in the histones possess the same fold. Homology was quantified with a unified procedure based on criteria of identity of key residues, primary structural homology and similarity of secondary structural potential. It has previously been shown that a set of other prokaryotic DNA-binding proteins have primary structural homology with the two lambda proteins. Homologies detected between the histones H4 and H2b and members of this set suggest that these histones also contain the putative DNA-binding fold. 相似文献
10.
Distribution of sulphate and iduronic acid residues in heparin and heparan sulphate 总被引:12,自引:12,他引:0
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1. A method was developed for determination of the uronic acid composition of heparin-like glycosaminoglycans. Polymers or oligosaccharides are degraded to monosaccharides by a combination of acid hydrolysis and deamination with HNO2. The resulting uronic acid monosaccharides (accounting for about 70% of the uronic acid contents of the starting materials) are isolated and converted into the corresponding aldono-1,4-lactones, which are separated by g.l.c. The calculated ratios of glucuronic acid/iduronic acid are reproducible within 5%. 2. Samples of heparin from pig intestinal mucosa (molar ratio of sulphate/disaccharide unit, 2.40) and heparan sulphate from human aorta (sulphate/disaccharide ratio, 0.46) were subjected to uronic acid analysis. l-Iduronic acid constituted 77% and 19% respectively of the total uronic acid contents. 3. The correlation between the contents of sulphate and iduronic acid indicated by this finding also applied to the fractionated deamination products of the two polymers. The sulphated fragments varied in size from disaccharide to octasaccharide (or larger) and showed sulphate/disaccharide molar ratios in the range of 0.05–2.0. The proportion of iduronic acid increased with increasing ester sulphate contents of the oligosaccharides. 4. Previous studies on the biosynthesis of heparin in a cell-free system have shown that l-iduronic acid residues are formed by C-5 epimerization of d-glucuronic acid units at the polymer level; the process requires concomitant sulphation of the polymer. The results obtained in the present structural study conform to these findings, and suggest further that similar mechanisms may operate in the biosynthesis of heparan sulphate. The epimerization reaction appears to be linked to the sulphation of hydroxyl groups but does not seem to require sulphation of the target uronic acid residues. The significance of sulphamino groups in relation to the formation of iduronic acid is unknown. 相似文献