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van Schaik  JP; Hawkins  IF  Jr 《Radiology》1985,155(3):829-830
A new technique is described for reversing the direction of the catheter tip during translumbar aortography, without the need for partial withdrawal of the catheter from the aortic lumen. The method ensures optimal delivery of contrast medium at the desired level, while avoiding the risk of retroperitoneal bleeding or dislodgement during catheter manipulation.  相似文献   
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Presumptive somatic cells of the copepod Cyclops kolensis specifically eliminate a large fraction of their genome by the process of chromatin diminution. The eliminated DNA (eDNA) remains only in the germline cells. Very little is known about the nature of the sequences eliminated from somatic cells. We cloned a fraction of the eDNA and sequenced 90 clones that total 32 kb. The following organizational patterns were demonstrated for the eDNA sequences. All do not contain open reading frames. Each fragment contains 1-3 families of short repeats (10-30 bp) highly homologous within families (87%-100%). Most repeats are separated by spacers up to 50 bp long. Homologous regions were found between fragments, motifs from 15-300 bp in length. Among fragments there occur groups in which the same motifs are ordered in the same fashion. However, spacers between the motifs differ in length and nucleotide composition. Ubiquitous motifs (those occurring in all fragments) were identified. Analysis of motifs revealed submotifs, each occurring within several motifs. Thus, motifs may be regarded as mosaic structures composed of submotifs (short repeats). Taken together, the results provide evidence of a high organizational ordering of the DNA sequences restricted to the germline. With this in mind, it appears incorrect to refer to this part of the genome as junk. Moreover, eDNA is redundant for only the somatic cells-its function is to be sought in germline cells.  相似文献   
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The use of the Bene-Anthony Family Relations Test is described and illustrated by three examples of child abuse. This test should be considered in the investigation of definite or suspected cases of abuse and as part of the preparation of court evidence.  相似文献   
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