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排序方式: 共有331条查询结果,搜索用时 15 毫秒
1.
Longitudinal analysis of allergen‐specific IgE and IgG subclasses as potential predictors of insect bite hypersensitivity following first exposure to Culicoides in Icelandic horses 下载免费PDF全文
2.
Time-frequency and complexity analyses for differentiation of physiologic murmurs from heart murmurs caused by aortic stenosis in Boxers 总被引:1,自引:0,他引:1
Höglund K Ahlstrom CH Häggström J Ask PN Hult PH Kvart C 《American journal of veterinary research》2007,68(9):962-969
OBJECTIVE: To investigate whether time-frequency and complexity analyses of heart murmurs can be used to differentiate physiologic murmurs from murmurs caused by aortic stenosis (AS) in Boxers. ANIMALS: 27 Boxers with murmurs. PROCEDURES: Dogs were evaluated via auscultation and echocardiography. Analyses of time-frequency properties (TFPs; ie, maximal murmur frequency and duration of murmur frequency > 200 Hz) and correlation dimension (T(2)) of murmurs were performed on phonocardiographic sound data. Time-frequency property and T(2) analyses of low-intensity murmurs in 16 dogs without AS were performed at 7 weeks and 12 months of age. Additionally, TFP and T(2) analyses were performed on data obtained from 11 adult AS-affected dogs with murmurs. RESULTS: In dogs with low-intensity murmurs, TFP or T(2) values at 7 weeks and 12 months did not differ significantly. For differentiation of physiologic murmurs from murmurs caused by mild AS, duration of murmur frequency > 200 Hz was useful and the combination assessment of duration of frequency > 200 Hz and T(2) of the murmur had a sensitivity of 94% and a specificity of 82%. Maximal murmur frequency did not differentiate dogs with AS from those without AS. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that assessment of the duration of murmur frequency > 200 Hz can be used to distinguish physiologic heart murmurs from murmurs caused by mild AS in Boxers. Combination of this analysis with T(2) analysis may be a useful complementary method for diagnostic assessment of cardiovascular function in dogs. 相似文献
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A. HüTtermann Marie-Therese Oelbe E. Fritz G. Schlechte A. Bytom A. D. Jungk Y. Okon E. Fallik Rivka Hadas S. Sarig E. Yahalom Sara Tal A. Hartmann B. Kishinevsky Debora Gurfel Rina Lobel Y. Kapulnik D. A. Phillips Y. Hadar Y. Chen E. Jurkevitch J. Katan A. Gamliel H. Ziegler I. Chet A. Ordentlich Hadar Kless A. Oppenheim Avia Zilberstein D. Holland J. Berman A. Zamir R. Kaufman N. Bawnik C. Koncz J. Schell 《Phytoparasitica》1987,15(2):141-147
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Petr Masner Christopher C. Steel Rolf Furter Hans Peter Isenring Gottfried Oesterhelt Hugo Ziegler Peter Zobrist 《Pest management science》1992,35(4):339-347
The activity of five experimental fungicides combining structural elements responsible for sterol C-14 demethylase inhibition and sterol nuclear double-bond transformations has been investigated by examining sterol accumulation in Ustilago maydis (DC.) Corda, inhibition of sterol-biosynthesis enzymes in Saccharomyces cerevisiae Meyer using a cell-free system and protective activity in cereals against Erysiphe graminis DC. and Puccinia coronata Corda. Combining the fenpropidin/fenpropimorph basic structure with a pyridine moiety offered no advantage in fungicidal activity. However, the combination of the pyrifenox structure with a morpholine moiety yielded a compound which was a good inhibitor of C-14 demethylase and Δ8 → Δ7 isomerase in vitro and gave good cereal protection. 相似文献
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Excretion and transmission of CSFV after vaccination with the CSF subunit marker vaccine "Porcilis Pesti" have been studied using the following different vaccination schedules: Group A--two vaccinations with an interval of 28 d, challenge 14 d after second vaccination (p.v2.); group B--two vaccinations with an interval of 14 d, challenge 14 d later; group C--two vaccinations with an interval of 28 d, challenge at time of booster vaccination; group D--two vaccinations with an interval of 14 d, challenge 7 d p.v2.; group E--single vaccination and infection 14 d later. After infection one sentinel pig was added to the vaccinated and infected pigs of each group. A single vaccination did not induce protective immunity against a CSFV challenge. Double vaccination at a four-week interval protected piglets from clinical infection, and neither viraemia and leukopenia nor virus excretion were detected if infected 14 d p.v2. Two vaccinations at a two-week interval followed by a challenge 7 d p.v2. led to a short viraemia on day 5 p.i. but without excretion of CSFV. Though all other vaccination schedules induced a reduction in virus shedding and a decrease in CSFV replication, in all these cases in-contact controls became infected. The results of transmission of CSFV are discussed in relation to a potential use of subunit marker vaccines in CSF control. 相似文献
8.
Pluripotent stem cells--model of embryonic development,tool for gene targeting,and basis of cell therapy 总被引:2,自引:0,他引:2
Embryonic stem (ES) cells are pluripotent cell lines with the capacity of self-renewal and a broad differentiation plasticity. They are derived from pre-implantation embryos and can be propagated as a homogeneous, uncommitted cell population for an almost unlimited period of time without losing their pluripotency and their stable karyotype. Murine ES cells are able to reintegrate fully into embryogenesis when returned into an early embryo, even after extensive genetic manipulation. In the resulting chimeric offspring produced by blastocyst injection or morula aggregation, ES cell descendants are represented among all cell types, including functional gametes. Therefore, mouse ES cells represent an important tool for genetic engineering, in particular via homologous recombination, to introduce gene knock-outs and other precise genomic modifications into the mouse germ line. Because of these properties ES cell technology is of high interest for other model organisms and for livestock species like cattle and pigs. However, in spite of tremendous research activities, no proven ES cells colonizing the germ line have yet been established for vertebrate species other than the mouse (Evans and Kaufman, 1981; Martin, 1981) and chicken (Pain et al., 1996). The in vitro differentiation capacity of ES cells provides unique opportunities for experimental analysis of gene regulation and function during cell commitment and differentiation in early embryogenesis. Recently, pluripotent stem cells were established from human embryos (Thomson et al., 1998) and early fetuses (Shamblott et al., 1998), opening new scenarios both for research in human developmental biology and for medical applications, i.e. cell replacement strategies. At about the same time, research activities focused on characteristics and differentiation potential of somatic stem cells, unravelling an unexpected plasticity of these cell types. Somatic stem cells are found in differentiated tissues and can renew themselves in addition to generating the specialized cell types of the tissue from which they originate. Additional to discoveries of somatic stem cells in tissues that were previously not thought to contain these kinds of cells, they also appear to be capable of developing into cell types of other tissues, but have a reduced differentiation potential as compared to embryo-derived stem cells. Therefore, somatic stem cells are referred to as multipotent rather than pluripotent. This review summarizes characteristics of pluripotent stem cells in the mouse and in selected livestock species, explains their use for genetic engineering and basic research on embryonic development, and evaluates their potential for cell therapy as compared to somatic stem cells. 相似文献
9.
P. Ziegler 《Journal of Cereal Science》1999,29(3):195
Cerealbeta-amylases are perhaps best known in terms of the vital role they play in releasing easily fermentable sugars from cereal grain starch to fuel the production of alcohol by yeast in brewing. The extent to which they have been investigated is indeed largely due to their significance in this economically important industry. However, cerealbeta-amylases are also, or could be, employed in many other aspects of the food industry and the analysis of starch, and they constitute valuable markers in cereal assessment and breeding studies. Quite apart from their practical significance, they are rewarding objects of biochemical and physiological research. They are interesting models for the study of enzyme polymorphism, post-translational modification and the differential expression of isoenzymes. In spite of their often high activitiesin situand all that is known about their generation, they are an enigma in that their physiological function, or even necessity, remains unclear. It has been recently recognised that there are two different categories of cerealbeta-amylases which exhibit different tissue and taxonomic specificities and physiological developmental patterns. The «classical»beta-amylases present at high activities in cereal seeds appear to be limited to the endosperm of the species of the Triticeae tribe of the Festucoideae subfamily of the Gramineae (wheat, barley and rye), whereas all cereals exhibit a different, tissue-«ubiquitous» form of the enzyme which is present at much lower activity levels. The physiological phenomenology and the usage of cerealbeta-amylases are discussed in relation to these two categories of enzyme. 相似文献
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