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《Médecine Nucléaire》2014,38(5):325-341
PET/CT with 18F-FDG is a test widely used in the evaluation of chest diseases as diverse as oncology indications and in particular the evaluation of pulmonary nodules, mediastinal disorders of the chest wall, breast lesions or even heart diseases including those of infectious valves. Despite the many precautions taken to the successful completion of the examination, a caution of the interpretation of the exam is required, given the pitfalls and artifacts inherent to the technique, respiratory and cardiac movements, the misrepresentation lesions (false positives of false negatives) or altered by the treatment. Their knowledge can minimize their impact on the interpretations and avoid the use of supplements investigations, sometimes invasive, or worse, administering a noxious or inappropriate treatment. The purpose of this paper is to describe the pitfalls and artifacts of PET/CT with 18F-FDG commonly found in the thoracic region but also to expose the various precautions that can help the conduct of the exam, the interpretation and even the optimal patient management.  相似文献   

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Until recently mycorrhizae had not been studied in the Antarctic region. Some studies have demonstrated that mycorrhizae occur in some southern circumpolar islands. This paper gives the first results on the mycorrhizae in the Kerguelen islands (Sub-antarctic). Twenty-one plant root systems, fixed in the field, were examined microscopically in the laboratory to determine their mycorrhizal status. No ectomycorrhiza, arbutoid or ericoid were noted. Six plant species showed vesicular arbuscular mycorrhizae: Ranunculus biternatus, Galium antarcticum, Festuca erecta, Poa kerguelensis, Agrostis magellanica and Poa annua. However, the mycorrhizal status varied according to the site studied.  相似文献   

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Summary Among species of the Ant genusLasius, nests sites and nesting habits differ according to the ecological requirements of every species. A classification of these habits has been outlined taking into consideration the complexity of the building techniques and the nature of the building materials. Whithin one single species there are populations differeing under these respects. This suggests the occurence of biological races.
Zusammenfassung Beobachtungen über die Lage und die Struktur des Nestbaues bei dem GeschlechtLasius in natürlichem Milieu, erlaubte es genau definierte oekologische Ansprüche festzustellen. Eine Einteilkung der artspeziefischen Sitten des GeschlechtesLasius konnte an Hand der angwendten komplessen Bauart kund des gebrauchten Materials aufgestellt werden. In einer gegebenen Art können jedoch mehrere Völker miteinbegriffen sein die sich durch einen verschiedenartigen nestbau unterscheiden; dies lässt uns annehmen, dass wir vor verschiedenen biologischen Rassen stehen.

Notes sur l'écologie et l'éthologie des espèces du genreLasius (Hymenoptera Formicid)
Résumé L'observation de l'emplacement et du mode de nidification des espèces du genreLasius dans leur milieu naturel a permis de mettre en évidence des exigences écologiques bien définies. De même, la complexité des techniques mises en uvre et le type de matérian employé lors de la construction des nids permettent de présenter un classement des murs des espèces du genreLasius. Une même espèce comporte des populations caractérisées par un mode de nidification différent, ce qui incite à penser que nous sommes en présence de races biologiques différentes.
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Boistel  J.  Lecomte  J.  Corabœuf  E. 《Insectes Sociaux》1956,3(1):25-31
Insectes Sociaux - With a classical system of amplification and registration, we have obtained electrical responses to variaous stimuli in isolated antennae of Wasps and Bees. A very light...  相似文献   

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Summary The author studies the developpement of the neuro-sensorial organs on the legs ofCalotermes flavicollis Fab. He has found that the outline of the neuro-sensorial organs developing in the larvae of the first instar do not change their structure. After each molt the number of sensorial organs increases and in correlation with this the small sensorial nerves ramify and secondary nerfs branch off the primary nerfs. On the legs of the larvae of the forth and mainly on those of the fifth instar the number of sensorial organs increases considerably. These latter are of different size and sit according to the region of the leg more or less densely together. The same is observed on the nymphs and imagines.A regression of the number and size of the sensorial organs accompanies the development of the pseudergates.The anatomy of the neurosensorial system of the third pair of legs is alike that of the second pair. The first pair of legs shows on the front surface the anatomy found inthe hind surface of the second pair of legs and the hind surface of the first pair the one of the front surface of the second pair.
Zusammenfassung Die Studie behandelt die Innervation der Beine vonCalotermes flavicollis Fab. Es wurde festgestellt, dass die gesamte sensoriel-nervöse Anlage schon bei den Larven des ersten Entwicklungsstadiums vorhanden ist und sich nicht mehr verändert, und dass nur mit jeder stattfindenden Häutung die Anzahl der sensoriellen Organe zunimmt und begleitet ist von einer reicher werdenden Verzweigung der Sinnesnerven. Gleichzeitig entstehen sekundäre Abzweigungen der Sinnesnerven, welche von den Hauptnerven ausgehen. Die Extremitäten der Larven des vierten und hauptsächlich des fünften Stadiums weisen eine sehr starke Zunahme der Sinnesorgane auf. Diese letzteren haben dann verschiedene Grösse und stehen je nach Region des Beines mehr oder weniger dicht beisammen. Dieselben Verhältnisse finden sich auch bei den Nymphen und Imagines.Eine zahlen- und grössenmässige Regression der Sinnesorgane wurde bei der Entstehung der Pseudergaten festgestellt. Die Anatomie der Sinnesorgane des dritten Beinpaares ist derjenigen des mittleren Beinpaares ähnlich. Die vordere Fläche des vordersten Beinpaares ist der hinteren Fläche des mittleren Paares ähnlich und die hintere Fläche derjenigen der Vorderfläche des mittleren Beinpaares.
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There are great concerns about the increasing incidence of abnormalities in male reproductive function. Human sperm counts have markedly dropped, and the rate of testicular cancer has clearly increased over the past four decades. Moreover, the prevalence rates of cryptorchidism and hypospadias are also probably increasing. It has been hypothesized that all these adverse trends in male reproduction result from abnormalities in the development of the testis during foetal and neonatal life. Furthermore, many recent epidemiological, clinical and experimental data suggest that these male reproductive disorders could be due to xenobiotics termed endocrine disruptors, which are becoming more and more concentrated and prevalent in our environment. Among these endocrine disruptors, we chose to focus this review on phthalates for different reasons: 1) they are widespread in the environment; 2) their concentrations in many human biological fluids have been measured; 3) the experimental data using rodent models suggesting a reprotoxicity are numerous and are the most convincing; 4) their deleterious effects on the development and function of the rat foetal testis have been largely studied; 5) some epidemiological data in humans suggest a reprotoxic effect at environmental concentrations at least during neonatal life. However, the direct effects of phthalates on human foetal testis have never been explored. Thus, as we did for the rat in the 1990s, we recently developed and validated an organotypic culture system, which allows maintenance of the development of the different cell types of human foetal testis. In this system, the addition of 10?4 M MEHP (mono-2-ethylhexyl phthalate), the most produced phthalate, had no effect on basal or LH-stimulated production of testosterone, but it reduced the number of germ cells by increasing their apoptosis, without modifying their proliferation. This is the first experimental demonstration that phthalates alter the development of the foetal testis in humans. Using our organotypic culture system, it is interesting to compare these results obtained in humans with the response to MEHP in the mouse and the rat testes to analyse the relevance of toxicological tests based on rodent models.  相似文献   

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Summary Among the species studied (Cr. scutellaris, Cr. auberti, Cr. sordidula, Cr. skounensis, Cr. vandeli), the formation of colonies from an isolated non social female seems an exception owing to the numerous adverse circumstances which both female and the young colony are liable to meet with. On the contrary, the greatest number of colonies are usually established by the coming out of offshoots followed by the adoption of a swarming female by the workers of the detached colony, on condition that this female has been fertilized. If not so, she is either massacred or expelled and left alone. On the other hand it is not necessary for the queen to originate from the same nest as the workers. If these do not succeed in adopting a female, the offshoot colony tends inevitably to perish sooner or later. Slight differences must be noted among the various species ofCremastogaster. AmongCr. scutellaris the foundation of colonies by isolated females is quite frequently to be observed while amongCr. auberti andCr. skounensis the establishment of colonies by off shoots detached from the nest seems to be the rule.  相似文献   

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《Comptes Rendus Palevol》2003,2(6-7):535-546
Ontogenetic heterochronies: a tool to study both variability and phyletic relationships? Example: Nigericeras, Ammonitina of the african Upper Cretaceous. The Nigericeras gadeni ontogenesis (Saharian Upper Cretaceous) is characterized by three ornamental stages: multi-tuberculate inner-whorls, ombilical bi-tuberculate medium-whorls, then finally smooth adult stage. Ontogenetic Heterochonies account for their adult variability, which extends between both paedomorphic (thick/ornamented) morphotype, and peramorphic (thin/smooth) morphotype. That species may take root in the older Pseudocalycoceras. A peramorphocline characterizes the evolution of these ammonites and their younger relatives, leading to different Nigerian and Nigerien, highly compressed taxa. Such morphologies seem to be related to shallow-water palaeo-environments. The general transgressive context leads to the progressive scarcity of their supposed ecological niches. To cite this article: P. Courville, C. Crônier, C. R. Palevol 2 (2003).  相似文献   

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