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91.
92.
Pulling the threads together: habitat diversity 总被引:2,自引:0,他引:2
Roy Watling 《Biodiversity and Conservation》1997,6(5):753-763
The dependence of fungi on host and habitat is emphasized and the reticulate pattern of the interactions explored. Habitat diversity, often defined by the vascular plant element, vertebrate and invertebrate associations, and non-phanerogamic mutualisms are considered. The role of man especially in changes in habitat availability is stressed. Infraspecific variability is mentioned. The diversity of habitats is as much a part of the Rio Convention as molecular, cellular and organismal variation. 相似文献
93.
Louis Prusse Yvon C. Chagnon France T. Dionne Claude Bouchard 《Obesity (Silver Spring, Md.)》1997,5(1):49-61
An update of the human obesity gene map up to October 1996 is presented. Evidence from Mendelian disorders exhibiting obesity as a clinical feature, single-gene mutation rodent models, quantitative trait loci uncovered in crossbreeding experiments with mouse, rat, and pig models, association and case-control studies with candidate genes, and linkage studies with genes and other markers is reviewed. All chromosomal locations of the animal loci are converted into human genome locations based on syntenic relationships between the genomes. A complete listing of all these loci reveals that only 4 of the 24 human chromosomes are not yet represented, i.e., 9, 18, 21, and Y. Several chromosome arms are characterized by the presence of several putative loci. The following arms include at least three such loci: 1p, 1q, 3p, 4q, 6p, 7q, 8p, 8q, 11p, 11q, 15q, 20q, and Xq. Studies with negative association and linkage results are also reviewed. 相似文献
94.
Brief overview of control of genetic expression by antisense oligonucleotides and in vivo applications 总被引:7,自引:0,他引:7
Gerald Zon 《Molecular neurobiology》1995,10(2-3):219-229
Over the past several years, the use of synthetic oligonucleotides and functional analogs thereof as a possibly general means
of controlling genetic expression has received widespread attention. Following a brief overview of some of the basic principles
and strategies for this approach, attention is focused here on summarizing some recent reports of in vitro and, in particular,
in vivo investigations in various animal models using phosphorothioate analogs of 2′-deoxyoligo-nucleotides. In view of these
findings, which include studies related to neurobiology, this field should find significant utility in applications of the
antisense method for controlling genetic expression. 相似文献
95.
Alexander Tschopp Augusto Cogoli Marian L. Lewis Dennis R. Morrison 《Journal of biotechnology》1984,1(5-6)
Attachment to a substrate and survival of human embryonic kidney (HEK) cells have been tested in an incubator installed in the flight-deck of the Space Shuttle ‘Challenger’ during its eighth mission.HEK cells are producing the enzyme urokinase and are presently investigated as candidates for electrophoretic separation in an apparatus developed and manufactured by McDonnell Douglas.Attachment of HEK cells to a substrate is mandatory for survival and production of urokinase after electrophoretic separation.Analysis of the samples shows that cells adhere, spread and survive in microgravity (< 10−3 ×g) conditions as well as the ground controls at 1 × g. This result represents an important step towards further bioprocessing in space. 相似文献
96.
97.
Effects of N-serve (2-chloro-6-(trichloromethyl)pyridine) formulations on nitrification and on loss of nitrate in sand culture experiments 总被引:1,自引:0,他引:1
Summary N-serve (2-chloro-6-(trichloromethyl)pyridine) was tested as an inhibitor of nitrification of ammonium or urea in sand cultures. Nitrification was reduced but not prevented by N-Serve present at between 5 and 20 ppm in solution or by weight of sand. In the presence of root debris and acetone, used in some experiments at 2–4 ml/l of nutrient to convey N-Serve, denitrification was stimulated under the same conditions and resulted in loss of a large proportion of nitrate, probably mainly as gaseous products and some nitrite. These losses were greater when N-serve was also present. There was also conversion of nitrate to an insoluble form in the sand. A smaller proportional loss of nitrate occurred in other treatments in the presence of root debris when N-Serve was added without acetone, either as the commercial formulation 24E or as a solid. Thus, using N-Serve to inhibit nitrification may encourage denitrifying organisms especially in the presence of carbon sources including root debris or acetone. Large decreases of nitrate reductase activity in plants produced by using N-Serve in the presence of ammonium or urea were caused as much by losses of nitrate in the presence of acetone as by prevention of nitrate formation. Other N-Serve treatments (solid or 24E) decreased enzyme induction by between 50 and 90 per cent as a result mainly of reduced nitrification. 相似文献
98.
阿胶,新阿胶,黄明胶,马皮胶,杂皮胶的质量对比研究:Ⅰ.氨基酸分析 总被引:1,自引:0,他引:1
本文用835-50型氨基酸自动分析仪测定了阿胶、新阿胶、黄明胶、马皮胶和杂皮胶中游离氨基酸和总氨基酸的含量,并计算出游离氨基酸、总氨基酸按侧链基团分类和按医药用途分类的相对含量。结果表明,各种氨基酸含量一般以驴皮胶为较高,但与其他几种胶比较并无显著差异,似可以猪皮马皮、牛皮代替驴皮。这也说明,单从氨基酸的含量来鉴别胶的种类和质量似乎不可行。 相似文献
99.
100.
Pierre Valeix Paul Preziosi Claude Rossignol Marie-Alice Farnier Serge Hercberg 《Biological trace element research》1992,32(1-3):259-266
Urinary iodine excretion was assessed in 642 healthy children aged 10 mo (n=243), 2 yr (n=183), and 4 yr (n=216) living in the Paris area and originating from continental France (60.3%), North Africa (13.8%), the West Indies (9.1%),
West Africa (8.3%), Southeast Asia (4.8%), and southern Europe (3.8%). Mild impairment of neurological (reflexes, tone, audiometry)
and intellectual development (Brunet-Lézine scale) was assessed in relation to iodine status. Iodine excretions (median values)
were 18.4, 11.9, and 10.9 μg/100 mL at 10 mo, 2 yr, and 4 yr, respectively, and risk of mild iodine deficiency (5–10 μg/100
mL) was 18.1%, 34.8%, and 38.3% for the same age groups. No relationship was found between anthropometry, global development
quotient, and iodine status. High hearing thresholds were more commonly associated with lower iodine excretion, suggesting
mild hearing defects. In spite of iodine prophylaxis, the risk of mild to moderate iodine deficiency still exists in France
and in a number of European countries. Evaluation of neurological sequels of borderline iodine status is a major public health
problem in European communities. 相似文献