Effect of essential amino acids on absorption of phenylalanine by rat intestine

Résumé L'effet d'un mélange des acidés aminés essentiels sur l'absorption de phénylalanine par l'intestin de rat a été étudié. On a trouvé que le mélange, s'il est en contact direct avec l'intestin, peut augmenter l'absorption de phénylalanine. Ces résultats sont interprétés et plusieurs hypothèses sont émises pour expliquer ce phénomène.     

Primary liver carcinogenesis induced by the pesticide 2-(4-tert-butylphenoxy0-1-methylethyl 2-chloroethyl sulphite (Aramite)]

Wistar rats were fed, during 56 weeks, a diet containing 5 g/kg of Aramite. At the end of the treatment, all the surviving animals show, on anatomo-pathological examination, malignant proliferation of the hepatic tissue and, in certain cases, of biliary ducts. This compound, proposed in the past as acaricide in agriculture, can thus be considered as a model substance for induction of malignant liver tumors.     

Global trends of whole-genome duplications revealed by the ciliate Paramecium tetraurelia

The duplication of entire genomes has long been recognized as having great potential for evolutionary novelties, but the mechanisms underlying their resolution through gene loss are poorly understood. Here we show that in the unicellular eukaryote Paramecium tetraurelia, a ciliate, most of the nearly 40,000 genes arose through at least three successive whole-genome duplications. Phylogenetic analysis indicates that the most recent duplication coincides with an explosion of speciation events that gave rise to the P. aurelia complex of 15 sibling species. We observed that gene loss occurs over a long timescale, not as an initial massive event. Genes from the same metabolic pathway or protein complex have common patterns of gene loss, and highly expressed genes are over-retained after all duplications. The conclusion of this analysis is that many genes are maintained after whole-genome duplication not because of functional innovation but because of gene dosage constraints.     

Isolation and partial characterization of ovine lactoferrin.

Ovine lactoferrin was isolated by ammonium sulfate precipitation and ion exchange chromatography. Comparative analyses were performed with the bovine protein. Differences in the amino acid compositions and the tertiary structure of the proteins were observed.     

基于RoBERTa与改进局部离群因子算法的专利新颖性测量

现有的专利新颖性测量方法需要依赖特定的领域知识以及专家的介入,性能差且耗时,为此,提出了一种不依赖特定领域知识及专家的全自动化系统的识别新颖性专利的方法。首先利用RoBERTa表示专利向量,以解决需要依赖技术领域的知识来表示专利的多义词问题,其次利用数据点的密度分布并结合信息熵改进局部离群因子算法（LOF）来确定离群点个数及数据点集,提高离群点的检测精度,结合RoBERT与改进的LOF在数值尺度上度量专利的新颖性。实验验证表明,所提方法测量的专利新颖性的得分与现有文献中的相关专利指标显著相关,并且识别出的新颖性专利具有更高的技术影响。     

Experimentally induced circular dominance relationships in a polygynous Polistes (Polistes dominulus Christ) wasp colony

Circular dominance relationships were set up in polygynous Polistes wasp colonies at the pre-emergence phase, by making use of the effects of priority of residence. The results are discussed in relation to various models which have been proposed to explain social dominance.     

Properties of an auxin-oxidising system fromLactobacillus bulgaricus

Résumé Un traitement à l'acide-indolylacétique (IAA) a pour effet d'induire — chezLactobacillus bulgaricus — un système inactivant l'IAA. Le pH optimum de ce complexe enzymatique est de 6.0 et sa température optimale de réaction de 32 °C. Cette induction est inhibée par des analogues de l'IAA (acides-indolyl carboxylique et-indolyl propionique;dl-tryptophane). L'apparition de cette « IAA-oxydase » permet de rendre compte, dans une large mesure, des effets de l'IAA sur la croissance des microorganismes testés.