首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
Struma ovarii is a monodermal variant of ovarian teratoma, which predominantly contains thyroid tissue. Malignant transformation and metastasis are very rare. The treatment of malignant struma ovarii remains controversial. We report the case of a patient with a recurrent struma ovarii, treated 18 years ago. The malignant transformation and metastases were treated with a combination of surgery and I131 ablation therapy.  相似文献   

2.
Ougandatherium napakense nov. gen. nov. sp., the earliest Rhinocerotidae Iranotheriinae from Africa. The Uganda Palaeontology Expedition discovered an exceptionally rich fossiliferous channel deposit at Napak I, Karamoja, in 1999, which yielded two partial skeletons of a new genus and species of early Miocene Rhinocerotidae, together with various other mammals and gastropods typical of Faunal Set I of East Africa. The age of the deposits on the basis of both faunal correlation (biochronology) and radio-isotopic dating is ca 19–20 Ma. The new genus and species is a hornless rhinoceros about the size of a small horse, with long slender limb bones and metapodials and hypsodont upper cheek teeth whose enamel is undulate, and fossettes cement-filled. Upper premolars possess an inner wall; this is clearly an iranotheriine morphology. As such it is the earliest known African member of this subfamily, close to the oldest member of the subfamily recently discovered at Bugti in Pakistan, a site whose age is about the same.  相似文献   

3.
4.
À la suite de captures de larves effectuées dans les Monts Bamboutos (Ouest du Cameroun) et de leurs mises en élevage, les auteurs décrivent le mâle, la nymphe et la larve d’Anopheles deemingi Service, 1970 dont seule une femelle était connue. Ils décrivent aussi la nymphe et la femelle d’une nouvelle espèce: Anopheles eouzani n. sp. qui a été capturée dans ces mêmes Monts Bamboutos mais à une altitude supérieure à 2 000 m.  相似文献   

5.
Lymphangioma is a benign tumor of the lymphatic system classified as simple, cavernous, or cystic depending on the size of the dilated lymphatic spaces within the tumor. Most cases present as a soft, cystic, slowly enlarging swelling in the neck and axilla in children, while the scrotum is a rare site. We report the case of a 39-year-old man who presented with a painless left hemiscrotal mass. On examination, the testes and spermatic cords were normal bilaterally. There was a firm, polycystic mass in the inferior portion of the left hemiscrotum. Scrotal ultrasound revealed normal testes, with a large complex cystic loculated mass. Histology demonstrated a cystic lymphangioma. The mass was completely excised. The patient remained well without recurrence with a follow-up of 6 months.  相似文献   

6.
7.
Sommaire Ce travail ne présente que quelques observations sur les premiers stades de dévelopment des colones deVespa orientalis. Les résultats ne sont que fragmentaires, mais permettent tout de même quelques comparaisons intéressantes avec d'autres espèces de Vespides.Nous avons observé que: 1o les reines de la Guêpe orientale sont très facilement élevées au laboratoire et y construisent et y pondent aisément. 2o les reines et les ouvrières dévorent leurs larves pour se nourrir ou pour alimenter les plus grosses larves; 3oles premières cellules d'un rayon sont assez irrégulières, elles ne prennent leur forme hexagonale que lorsqu'elles sont entourées de cellules voisines; 4o le matériau utilisé pour édifier les cellules est assez divers; 5o les reines ne réparent pas les trous effectués dans les parois des cellules; 6o les reines ne s'intéressent au petites brèches du bord des cellules que lorsqu'elles sont en train d'allonger les parois des cellules voisines; 7o les ouvrières ont un comportement comparable à celui des reines lorsqu'elles se nourrissent ou nourrissent les larves ou lorsqu'elles construisent; 8o les reines, les larves et les ouvrières échangent de la nourriture, du liquide; 9o la seule division du travail dans la colonie est celle qui existe entre la reine qui ne fait plus que pondre et les ouvrières qui s'affairent à toutes les occupations; 10o le cycle évolutif du développement du couvain que nous décrivons peut être variable, suivant les colonies, dans les mêmes conditions expérimentales.
Summary These first observations only deal with the early growing of new colonies in an israelian laboratory: the building of the first comb, the queen's hatching and behavior, the first workers' behavior have been observed.1o The breeding of the queens and the workers is easy: they build fine combs, where the queens lay their eggs; 2o Queens and workers cannibalism has been pointed out; 3o The first cells are very odd; they become hexagonal when they are surrounded with other ones; 4o The materials used into the combs are various, paper, earth ; 5o Many little holes has been observed inside the walls of the cells; they are never closed; 6o The experimental gaps in the cells are only repaired when the wasps lengthen the neighbour cells; 7o The building and breeding bekavior of the queens and the workers are similar; 8o The queens, the larvae, the workers exchange food, liquids; 9o There is no division of the work between the first workers, but between the queens and the first workers; 10o In our experiments, the brood's evolutive cycle is different from one colony to the other one.
  相似文献   

8.
Summary Nectria galligena is grown in synthetic medium. Experiments are carried out with suspensions of washed mycelium, incubated and stirred with indole-3-acetic acid (IAA) or IAA 2-14C. Auxin degradation is quicker with either acid pH or young mycelium. Two indolic compounds are identified in the course of this metabolism: indole-3-aldehyde (IAld) and indole-3-carboxylic acid (ICA).A correlation is supposed to exist between the increase of auxin contained in cultures of Nectria and IAA catabolism as it lessens with age and alcalin pH.
Dans le texte les abréviations suivantes seront employées IAA Acide Indolyl-3-acétique - IAld Indolyl-3-aldéhyde - ICA Acide Indolyl-3-carboxylique - DPH 2,4-dinitrophénylhydrazine - DMCA Paradiméthylaminocinnamaldéhyde  相似文献   

9.
The lake sediment record was used to reconstruct past vegetation dynamics and human impacts from the middle Neolithic (6500 cal. b.p.) to the Middle Ages (1500 cal. b.p.) around Lac d’Antre in the southern Jura mountains of France. This lake was surrounded by the Gallo-Roman sanctuary of Villards d’Héria, which has been widely investigated by archaeologists and enables a comparison between palaeoenvironmental proxies and archaeological data. Pollen and microscopic charcoal analyses were conducted on a 500 cm sediment core with eleven radiocarbon dates providing the chronological control. In a mixed oak woodland context, the successive development of Taxus, Fagus and Abies were mainly caused by climatic variations during the Neolithic, in which there was weak human impact. The first significant signs of human activity were detected during the Bronze Age from 3900 cal. b.p., followed by an increase of human pressure and woodland clearances during the Iron Age, from 2700 cal. b.p. The occupation of the Gallo-Roman sanctuary was continuous with the Iron Age occupation. All the analysed palaeoenvironmental data indicate that the strongest human impact occurred during the Gallo-Roman period, which matches the occupation of Villards d’Héria previously dated by archaeologists from 2000 to 1700 cal. b.p., 1st to 3rd century a.d. Moreover, there appears to have been a new period of human settlement close to the lake at the beginning of the Middle Ages. The low charcoal accumulation rate (CHAR) recorded during the Bronze and Iron Ages suggests that fire was not the main agent used to clear the dense woods to create new cultivated fields and pastures. High CHAR values recorded during the Roman period may represent fire use for domestic and agro-pastoral activities.  相似文献   

10.
Potentiometric properties of a fully deacetylated chitosan have been investigated using pH and c.d. measurements. The same studies have also been performed in the presence of copper II ions in order to determine the mode of interaction and to deduce the stoichiometry of the complex formed under these conditions.  相似文献   

11.
12.
We aim to provide a long-term ecological analysis of land-use and floristic diversity in the transition from traditional to modern land-use management in the time a.d. 1800–2008 in southern Sweden. We use the Regional Estimates of Vegetation Abundance from Large Sites (REVEALS) model to quantify land-cover changes on a regional scale at 20-year intervals, based on the fossil pollen record. Floristic richness and evenness are estimated using palynological richness and the Shannon index applied to the REVEALS output, respectively. We identified a transition period of 60?years between 1880 and 1940 when the total tree cover increased and the tree composition changed from deciduous to coniferous dominance. Within the shrinking area of open land, arable land taxa expanded, while the number and coverage of herbs in the remaining grasslands decreased. The succession from open grasslands to more tree-covered habitats initially favoured palynological richness, which reached its highest values during the first 40?years of the transition period. The highest REVEALS-based evenness was recorded in the time of traditional land-use and at the beginning of the transition period, reflecting higher habitat diversity at these time intervals. Our results support a more dynamic ecosystem management that changes between traditional land-use and phases of succession (<40?years) to promote floristic diversity. We have developed and applied a palaeoecological methodology that contributes realistic estimates to be used in ecosystem management.  相似文献   

13.
《L'Anthropologie》2023,127(1):103101
The Mesolithic is a fascinating period, where ancient traditions are tilting towards a new paradigm. Many changes can be recognised without being able to establish a real split with the Palaeolithic. Far from being just a bridge towards the Neolithic, the Mesolithic is truly a new and stable metaphysical structure. In our article, we are interested in the structural mechanisms by which Palaeolithic metaphysics slides towards the Mesolithic, where the individual occupies a central role.  相似文献   

14.
15.
A revision of fossil plants, with preserved structures, collected in the Upper Devonian of the Donetz Basin (Ukrainia) allows us to describe 2 Lycophyta. One of them is a new species: Colpodexylon (?) schopfii nov. sp.  相似文献   

16.
Macroscopic charred remains of Spinacia oleracea L. (Amaranthaceae) have been found in the Pyrenean village of Montaillou, France, in several contexts of a house dated to the end 12th–mid 13th century a.d. This is the first archaeobotanical record of this vegetable in France and the earliest European archaeobotanical material so far found. The paper presents the morphological criteria used for identifying the charred remains of the species. After a review of archaeobotanical finds in Europe, hypotheses on the economic status of this vegetable, which is unknown as a wild plant in Europe, are discussed with reference to medieval written and illuminated sources and to archaeological deposits. It appears that Spinacia was first introduced into France from Moorish Spain where it was cultivated at least since the 11th century. The French evidence of Spinacia thus represents a milestone in the history and geographic diffusion of this vegetable into temperate Europe.  相似文献   

17.
《Comptes Rendus Palevol》2002,1(7):615-627
Fossil invertebrates collected or received by Alcide d’Orbigny, all his life long, have been brought together in a renowned collection that is very rich in terms of both species and specimens. The collection has resulted from a huge palaeontological work. Study of faunas from numerous French sites led Alcide d’Orbigny to do biostratigraphical comparisons and to erect geological stages, the definitions of which rest on their stratotypes. His wide knowledge of European fossil faunas was strengthened by a more global palaeobiogeographical view derived from his travel in South America. The d’Orbigny collection is housed in the ‘Muséum’ of Paris and is often visited by experts.  相似文献   

18.
《L'Anthropologie》2019,123(1):100-115
Located in northern Scandinavia, rock art sites from Alta are the silent witness of ancient people. Considering landscape, surfaces and engravings gives the opportunity to understand the relation of pictures to their context. Simultaneous understanding of both rock surface and picture offer to reach a graphical discourse. On the other hand mythology gives a new perspective to engravings and integrates them into a global values’ system. Power over representation and the rise of sacred feeling produce by those engravings create a special space closer to a higher reality. In that more than natural space respect to precise rules is of the first importance. By a metaphysic's knowledge, the shaman insures good fortune and well-being to the entire group. This paper offers to consider those different aspects and to shed light on their importance.  相似文献   

19.
The aim of this paper is to discuss implications of different resolution scales of both time and space in studies of past land use and past vegetation, both historical and palaeoecological. The paper gives examples of short term-variation, long-term changes, small spatial scale differences and regional differences in land use, studied through historical sources in four regions in south central Sweden. It also discusses the difficulty of interpretation of forest vegetation in old cadastral maps. Historical sources can show dynamics on the fine temporal and spatial scales that are difficult to capture with pollen analysis. On the other hand, pollen analysis has unique possibilities for the study of time periods where historical records are lacking. Therefore the combination of several disciplines is likely to be productive in aiding understanding past land use and vegetation. However, there are important limitations in using the information in cadastral maps and other historical sources to interpret and quantify past vegetation.  相似文献   

20.
The tips of the rhizomorphs ofSphaerostilbe repens transferred on agar medium regenerate some aggregated organs without an intermediate mycelium stage. Each extremity of the drawn rhizomorphs can give rise to eoremia on its air face and to rhizomorphs on the contact with tho culture medium. These heterogeneous environmental factors impose polarized regeneration, easily inverted, upon the rhizomorphs. Nevertheless, a residual and stable polarity remains; it is attributed to the apex which is more capable of bearing new organs than the other extremity. Tho efficiency to regenerate depends on the ago of collulos and on tho size of tho rhizomorph tip; howover it is very difficult to provent the formation of new aggregated organs.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号