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To study the noteworthy nest building behavior of the nymph of the Brazilian Rainforest cicada Guyalna chlorogena (Walker) during the last year of its underground life, we monitored a large number of edifices, consisting of a vertical well (up to 1 m deep) with a turret (20 to 40 cm tall) on top, and we also performed experiments. We have shown that the buildings are occupied by a single nymph, male or female, which increases the height of its turret each night by about 3 cm, during a short active growing phase. The nymph softens and reshapes the apex by pushing upwards a lump of freshly mixed soaked clay, without any opening present, i. e., without ever exposing itself to the outside. We also established that the nymph is very active once its building is achieved. For example, it restores the height of the turret to its original value when shortening and opens the top of its building in case of variation of environmental parameters. Finally, we have shown how the nymph opens its edifice to reach the outside for molting into an adult stage (imago). With this work, we contributed to a better understanding of the nesting behavior of Amazon cicadas.

Carbon xerogels of different porosity were synthesized in this work. Several post-treatments (carbonization and chemical activation processes) were studied and it was observed that the treatment applied determines the porous texture. It was possible to produce from highly microporous carbon xerogels with a significant amount of narrow mesopores (sample AOX) to micro-mesoporous xerogels that preserve the original mesoporosity of precursor material (ACX xerogel). Once the textural properties of synthesized carbon xerogels were evaluated, the most suitable carbon xerogel for use as electrode in supercapacitors was selected.

In this work it will be shown that the mechanical reinforcement of polymer composites using carbon nanotubes is dependant on the total surface area of carbon nanotubes dispersed into the polymer matrix. Furthermore, it will be shown that the total length of carbon nanotubes dispersed in the polymer matrix does not have any influence on the mechanical properties. Four differently produced carbon nanotube samples were introduced into a polyvinyl alcohol matrix and it can be reported that the sample with the smallest diameter, thus the nanotube sample with the highest surface area, increased mechanical properties such as tensile modulus by 120% while adding less than 1wt% of carbon nanotubes. Measurements were accomplished on bulk free standing polymer films by tensile testing.

La femme enceinte est aujourd’hui frequemment exposee a des traumatismes plus ou moins graves. Les accidents de la circulation et la violence urbaine sont des causes importantes de traumatismes maternels et foetaux. Ce type d’accident pose de multiples problemes medicaux, obstetricaux, psychologiques, ethiques, legaux, d’assurances, de prevention, etc.

Un mosaicisme chromosomique apparemment limite au placenta (MCP) est trouve dans 1 a 2% des diagnostics prenataux par choriocentese. Le MCP semble le plus souvent ne pas avoir de consequence fœtale fâcheuse, puisque la grande majorite des enfants nes apres un «faux positif» a la choriocentese sont parfaitement normaux. Cependant, un MCP est associe rarement a des problemes pre- et perinataux, tels qu’un retard des croissance intrauterine ou une letalite pre- ou perinatale. Parmi les facteurs qui augmentent le risque d’une dysfonction/insuffisance placentaire, il faut certainment inclure le contenu genique du chromosome implique et la proportion de cellules normales par rapport aux aneuploi-des. L’origine parentale du chromosome manquant/supplementaire et la possibilite d’une disomie uniparentale de la lignee «normale» doivent aussi etre considerees.

Le depistage, le diagnostic et le traitement des maladies virales dans la periode perinatale posent souvent a l’obstetricien et au neonatalogue de difficiles problemes que la litterature actuelle n’aide pas toujours a bien resoudre. Nous avons tente de resumer ici aussi clairement que possible ce qui nous semble representer une attitude logique a l’egard de quatre de ces infections: l’infection par le VIH (virus de l’immunodeficience humaine), l’hepatite B, l’herpes et la varicelle. Nous avons surtout consacre les quelques lignes qui suivent au diagnostic, a l’attitude souhaitable au moment de l’accouchement, a la protection du nouveau-ne et a la protection du personnel medical et paramedical.

L'echocardiographie foetale (bidimensionnelle en temps reel et en M-mode) se pratique chez nous depuis 3 ans dans le cadre d'une consultation specialisee. L'indication pour une evaluation cardiaque a ete posee a cause d'un facteur de risque familial chez 78 cas, pour des raisons foetales chez 78 grossesses, pour un probleme maternel 9 fois. Dans 25 cas, aucune indication specifique n'a existe. L'examen echocardiographique a ete pratique entre la 18eme et la 39eme semaine de la grossesse (moyenne: 28eme semaine). Parmi 190 grossesses, dont 169 a haut risque, nous avons mis en evidence 33 cas de malformation cardiaque (17,4%) dont 14 cardiopathies complexes graves et 3 arythmies isolees (1,6%) mais necessitant un traitement pendant la grossesse. Les porteurs de telles malformations ont beneficie d'une surveillance appropriee et de soins immediats lors de leur naissance. Dans 154 grossesses, les futurs parents ont pu etre rassures.

Immunohistochemical techniques and direct measurements of pregnancy-associated plasma protein A (PAPP-A) have demonstrated the presence of PAPP-A in trophoblast and decidua. The purpose of the present study was to investigate the possibility that these tissues are capable of producing PAPP-A in vitro. Trophoblast and decidua were obtained from term deliveries and from legal surgical terminations of pregnancy (7 to 12 weeks). In addition to trophoblast and decidua, myometrium was also obtained during two hysterectomies in the first trimester of pregnancy. Tissues were incubated in medium 199 at 37 degrees C under an oxygen/carbon dioxide atmosphere. Media containing either pregnancy-associated serum or non-pregnancy-associated serum were changed after 8 hours of incubation in medium 199 alone. In addition to PAPP-A, human placental lactogen (hPL) and prolactin (Prl) were measured in homogenates and media by radioimmunoassays in order to confirm the viability of the cultured tissues. Addition of pregnancy-associated serum to the media induced a significant release of PAPP-A from trophoblast and decidua when compared to that in control cultures. Non-pregnancy-associated serum had no effect. Myometrium did not release any measurable PAPP-A into the medium even in the presence of pregnancy-associated serum. Cycloheximide added to pregnancy-associated serum significantly inhibited the release of PAPP-A from trophoblast and decidua. These last tissues, irrespective of the culture condition, released significantly more PAPP-A as well as hPL and Prl than was initially present in the tissue. These data demonstrate that PAPP-A is released in vitro by trophoblast and decidua (but not by myometrium) and that this release can be magnified by a factor present only in pregnancy-associated serum. The release of PAPP-A, hPL, and Prl is considered as a de novo production since concentration of these proteins are higher in media and tissues after incubation compared to concentrations initially present in the tissue before culture and since cycloheximide significantly inhibits the release of PAPP-A, Prl, and hPL from the cultured tissues.

The thermal behaviour of the 1st stage Li(THF)2.13C12 ternary graphitide was studied in the range 320 K to 10 K. At 320 K, the THF molecules present hindered motions, and the identity period I c = 12.45 A is explained by the existence of a double layer of THF molecules, with their mean plane tilted at about 55° with respect to the c axis. Upon cooling, a first order transition from 270 K to 210 K leads to the appearance of a new phase ( I c = 10.63 A at 10 K), and simultaneously to locking of the motions. At low temperature, the 1H NMR spectra, the values of Ic and of the 001 intensities are compatible with a double layer of molecules parallel to the graphene planes. Lowering the temperature increases the constraints along c, which causes the collapse of the Li(THF)x complexes.

Summary. Vaginal fluid levels of prolactin (Prl), α-fetoprotein (AFP) and human placental lactogen (hPL) were assayed to investigate their usefulness in the diagnosis of ruptured membranes. Fifty-two patients at term were divided into those with intact membranes, and those with ruptured membranes. In patients with intact membranes the concentration of all three substances was low with few exceptions. The mean vaginal concentrations of the three proteins were significantly higher in patients with ruptured membranes, but low values were also found in this group. It is concluded, that because of the overlap between the values, Prl, AFP and hPL measurements in vaginal fluid do not represent a useful advance in the assessment of rupture of the membranes.

Plasma beta 2 microglobulin (beta 2m) levels have been measured by radioimmunoassay in normal pregnant women, in two successive pregnancies of a woman who shares HLA antigens with her husband, in normal twin pregnancies, in toxemic pregnancies and in hydatidiform moles. During normal pregnancy, plasma beta 2m levels decrease reaching a minimum at week 14 and increase thereafter to a maximum at week 34. In the two successive pregnancies of the one patient with HLA compatibility, beta 2m concentrations were significantly lower than in normal pregnancies. Women with monozygotic twins had significantly less beta 2m than women with heterozygotic twins. Toxemic patients bearing female fetuses had also statistically lower beta 2m levels than toxemic women with male fetuses. Patients suffering from hydatidiform moles had beta 2m levels in the range of normal pregnant patients. Since circulating beta 2m is produced by lymphocytes one might assume that low beta 2m levels reflect a reduced activity of lymphocytes. The results presented here allow to propose a hypothesis which will have to be verified that reduced beta 2m levels are associated with an increased feto-maternal histocompatibility.

Human placental lactogen (hPL), alpha fetoprotein (AFP), prolactin (PRL) and pregnancy-associated plasma protein-A (PAPP-A) were measured by radioimmunoassay in plasma, in homogenates of trophoblast, decidua, chorion, amnion and in amniotic fluid from 10 patients after non-complicated term delivery. Plasma samples and homogenates of trophoblast and decidua were also collected from 10 patients undergoing surgical termination of pregnancy between 7 and 12 weeks gestation. In addition, plasma and endometrial samples from 10 patients undergoing hysterectomy for other indications than malignancy were analysed for comparison. The highest tissue concentrations of hPL, AFP and PRL corresponded in each case to the known site of synthesis. For PAPP-A the highest concentration was found in maternal plasma at term [238.8 +/- 75.6 (SEM) micrograms/ml]. The highest tissue concentration was found at term in the decidua (57.0 +/- 2.0 micrograms/g), more than three times higher than that in the trophoblast (16.9 +/- 5.4 micrograms/g). The concentrations of PAPP-A in endometrial samples from non-pregnant women (1.9 +/- 0.6 micrograms/g) was 40 times higher than that in the corresponding plasma samples (0.05 +/- 0.02 microgram/ml). These observations point to the decidua as a possible source of PAPP-A.