Search

Air pollution has significant health effects worldwide, and airborne particles play a significant role in these effects. Ultrafine particles (UFPs) have an aerodynamic diameter of 0.1 μm or less, can penetrate deep into the respiratory tree, and are more toxic due to their large specific surface area, which should adsorb organic compounds. The aim of this study is to show the toxicological effects of UFPs with high organic content at low dose on BEAS-2B cells through at air-liquid interface (ALI) exposure using a Vitrocell® technology and a miniCAST (Combustion Aerosol Standard) generator. In conjunction with this approach, chemical analysis of particles and gas phase was performed to evaluate the presence of polycyclic aromatic hydrocarbons (PAHs). Chemical analyses confirmed the presence of PAHs in UFPs. With this experimental setup, exposure of the BEAS-2B cells induced neither cytotoxicity nor mitochondrial dysfunction. However, an increase of oxidative stress was observed, as assessed through Nrf2, NQO1, HO-1, CuZnSOD, MnSOD, and Catalase gene expression, together with significant induction of genes related to xenobiotic metabolism CYP1A1 and CYP1B1. Negative regulation of inflammatory genes expression (IL-6 and IL-8) was present three hours after the exposition to the UFPs. Taken together, this experimental approach, using repeatable conditions, should help to clarify the mechanisms by which organic UFPs induce toxicological effects.

Powder neutron diffraction measurements were carried out to investigate the magnetic structure of the antiferromagnet NdRh2Zn20. The magnetic reflections observed for T ≤ 1.0 K are indexed by the propagation vector of k = (1/2, 1/2, 1/2). From the analysis of the intensity of magnetic reflections, a magnetic structure described by the Γ6 representation is proposed. The magnetic moments are parallel to the [ 11 2 ¯ ] or [ 1 ¯ 10 ] direction and stacked with a sequence of up-up-down-down along the [111] direction.

Narcolepsy-cataplexy was first described in the late 19th century in Germany and France. Prevalence was established to be 0.05 % and a canine model was discovered in the 1970s. In 1983, a Japanese study found that all patients carried HLA-DR2, suggesting autoimmunity as the cause of the disease. Studies in the canine model established that dopaminergic stimulation underlies anti-narcoleptic action of psychostimulants, while antidepressants were found to suppress cataplexy through adrenergic reuptake inhibition. No HLA association was found in canines. A linkage study initiated in 1988 revealed in hypocretin (orexin) receptor two mutations as the cause of canine narcolepsy in 1999. In 1992, studies on African Americans showed that DQ0602 was a better marker than DR2 across all ethnic groups. In 2000, hypocretin-1/orexin A levels were measured in the cerebrospinal fluid (CSF) and found to be undetectable in most patients, establishing hypocretin deficiency as the cause of narcolepsy. Decreased CSF hypocretin-1 was then found to be secondary to the loss of the 70,000 neurons producing hypocretin in the hypothalamus, suggesting immune destruction of these cells as the cause of the disease. Additional genetic studies, notably genome wide associations (GWAS), found multiple genetic predisposing factors for narcolepsy. These were almost all involved in other autoimmune diseases, although a strong and unique association with T cell receptor (TCR) alpha and beta loci were observed. Nonetheless, all attempts to demonstrate presence of autoantibodies against hypocretin cells in narcolepsy failed, and the presumed autoimmune cause remained unproven. In 2009, association with strep throat infections were found, and narcolepsy onsets were found to occur more frequently in spring and summer, suggesting upper away infections as triggers. Following reports that narcolepsy cases were triggered by vaccinations and infections against influenza A 2009 pH1N1, a new pandemic strain that erupted in 2009, molecular mimicry with influenza A virus was suggested in 2010. This hypothesis was later confirmed by peptide screening showing higher activity of CD4Narcolepsie : une maladie auto-immune affectant un peptide de l’éveil liée à un mimétisme moléculaire avec des épitopes du virus de la grippe.La narcolepsie et la cataplexie sont décrites pour la première fois à la fin du XIX

IF 7.191 (2017); International audience; BACKGROUND:Previous studies showed that high and low body mass index (BMI) was associated with worse prognosis in early-stage colorectal cancer (CRC), and low BMI was associated with worse prognosis in metastatic CRC (mCRC). We aimed to assess efficacy outcomes according to BMI.PATIENTS AND METHODS:A pooled analysis of individual data from 2085 patients enrolled in eight FFCD first-line mCRC trials from 1991 to 2013 was performed. Comparisons were made according to the BMI cut-off: Obese (BMI ≥30), overweight patients (BMI ≥ 25), normal BMI patients (BMI: 18.5-24) and thin patients (BMI

The nature and formation conditions of the ground state and the dynamic magnetic response (the magnetic excitation spectrum) of the YbB12 and Sm(Y)S systems with the nonmagnetic ground state have been studied using inelastic neutron scattering.

Electron doping of the Kondo-insulator YbB12 has been achieved by substitution tetravalent Zr for Yb in the newly synthesized Yb0.8Zr0.2B12 solid solution and substitution carbon for B in boron cluster network with concentration order of 1% (Yb(B0.99C0.01)12. Neutron scattering measurements of the dynamical magnetic response are reported and analyzed. Zr doping transforms the spin-gap spectral response into a pseudogap shape and makes its temperature evolution much smoother than in the Yb1-xLuxB12 family studied previously. Carbon doping influences on the energy range of ground state excitation spectrum but does not suppress the magnetic gap. The results obtained are discussed in connection with the contribution of different interactions into the formation of the ground state for the Kondo-insulator.

Strain engineering has been in the heart of CMOS technology for over a decade. However, the effectiveness of conventional strain elements, such as stress liners, embedded S/D stressors, and stress memorization, is significantly reduced when device gate pitch is scaled below 100 nm as needed for 14nm node and beyond. Substrate strain engineering, where the channel itself is formed out of a strained semiconductor, e.g. in the form of strained silicon directly on insulator (SSDOI) or strained SiGe-on-insulator has the advantage that the strain is independent of the device pitch or gate length as long as the active region is made sufficiently long and the strain is maintained throughout the device processing. We have already shown that in a FinFET structure the starting biaxial strain in the SSDOI substrate is converted to a more beneficial uniaxial strain, strain can be maintained throughout typical thermal processing, and demonstrated roughly 15% increase in NFET performance in deeply scaled FinFETs. However, this is still far less than the performance gain we reported recently in ETSOI devices. In this work, for the first time we report NFET performance gain in SSDOI FinFETs fabricated with contacted gate pitch (CGP) down to 64nm.

International audience; We report the results of a comprehensive study of the exchange interactions in Co-doped ZnO using inelastic neutron scattering, electron paramagnetic resonance, and magnetic property measurements. In particular, we observe an unprecedentedly strong spatial anisotropy of the two nearest-neighbor exchanges, J (1) = −25.6 ± 0.3 K and J (2) = −8.5 ± 0.4 K, along with the distant-neighbor J values of ferromagnetic sign. We argue that the superexchange mechanism alone cannot account for the obtained data and we suggest that an additional mechanism leading to a strong ferromagnetic spin coupling is responsible for these findings. We also discuss the origin of this ferromagnetic mechanism.

We have measured the electrical resistivity of several quasi 1-D chalcogenides between 1.2 and 300K and from ambient pressure up to 25GPa. On NbSe 3 we find that the high temperature charge density wave (CDW) transition T 1 disappears at a pressure of about 3.5GPa, where the superconducting transition temperature T c jumps to ∼5K. The similar pressure dependence of the logarithmic pressure derivative of both T 1 and T c above this pressure suggests the existence of independent superconducting states. On m-TaS 3 we observe a maximum on the T 1 -P variation at ∼3.5GPa, that we attribute to a CDW transition temperature strongly diminished by 1-D fluctuations that are reduced at low applied pressures, with T 2 behaving in a monotonous decreasing way with pressure. While on o-TaS 3 the CDW that develops at 210K at ambient pressure, gives way to a superconducting state of T c ∼3K at a pressure of 6.5GPa. The behaviour of (TaSe 4 ) 2 I is scaled to the precedent, with a higher critical pressure of 15GPa that induces the appearance of a superconducting state with T c =2.5K.

We have measured the electrical resistivity as a function of temperature up to pressures of 25 GPa of pure fullerenes C60, C70 and the compound C60I4. For the three materials the best fit in our temperature range corresponds to a three-dimensional variable-range hopping conductivity, signature of an important disorder. A dramatic decrease of the resistivity, by two orders of magnitude per GPa, is observed at low pressures. However, no metallic state is attained as all the samples present a phase transformation in the high-pressure range, probably originated by the crossover from sp2 to sp3 hybridization of the carbon orbitals at high pressures.

The phonon dispersion relations in MnSi were measured using inelastic neutron scattering. At the same time, calculations of the phonon spectra of MnSi were carried out in the framework of density functional theory in the local density and the generalized gradient approximations. The calculations match most of the phonon modes in the frequency range up to 40 meV. The phonon density of states obtained on the basis of the phonon dispersion was used to estimate the lattice contribution to the specific heat of MnSi.

Elastic and inelastic neutron scattering measurements have been performed on powder and single-crystal samples of orthorhombic CeRu2Al10. The order forming below T0 = 27 K was identified as a long-range antiferromagnetic state with the wave vector k = (1,0,0). The magnetic spectral response in the ordered phase, measured on powder, is characterized by a spin gap and a pronounced peak at 8 meV, whose Q dependence suggests a magnetic origin. Both features are suppressed when temperature is raised to T0, and a conventional relaxational behavior is observed at 40 K. This peculiar spin dynamics is discussed in connection with recent magnetization results for the same compound., 5 pages, 5 figures, International Conference on Heavy Electrons 2010 (Tokyo Metropolitan University, September 17 - 20, 2010), to be published in Journal of the Physical Society of Japan. Typo corrected p. 3: "sites denoted 1 and 3" => "1 and 4"

We present UTBB devices with a gate length (L G ) of 25nm and competitive drive currents. The process flow features conventional gate-first high-k/metal and raised source/drains (RSD). Back bias (V bb ) enables V t modulation of more than 125mV with a V bb of 0.9V and BOX thickness of 12nm. This demonstrates the importance and viability of the UTBB structure for multi-V t and power management applications. We explore the impact of GP, BOX thickness and V bb on local V t variability for the first time. Excellent A Vt of 1.27 mV·µm is achieved. We also present simulations results that suggest UTBB has improved scalability, reduced gate leakage (I g ) and lower external resistance (R ext ), thanks to a thicker inversion gate dielectric (T inv ) and body (T si ) thickness.

We have measured the electrical resistivity of NbSe3 between 2 K and room temperature up to a pressure of 7.2 GPa. At P1 = 3.5 GPa we observe the extinction of the high-temperature charge density wave (T1-CDW) and the enhancement of the superconducting critical temperature Tc to 5 K. The logarithmic pressure slopes of T1 (P P1) are found to be practically equal. A similar behaviour had been reported previously at lower pressures for T2 (P < P2) and Tc (P2 < P < P1) in the distorted state. We discuss these results in terms of an anisotropic superconducting state in NbSe3, with different gaps associated with different types of chains.

Neutron powder diffraction measurements have been performed on CexNd1−xB6 (x = 0.5, 0.6, 0.7, and 0.8) solid solutions to determine the type of magnetic order occurring in these compounds as a result of the interplay between magnetic dipole exchange and antiferroquadrupolar interactions. In the Ce-rich range, the sequence of two magnetic phases, with an incommensurate order [k = (1/4 − δ, 1/4 − δ, 1/2)] forming below T N followed by a lock-in–type transition at lower temperature, is quite similar to that reported earlier for CexPr1−x B6. For x = 0.5, on the other hand, the same antiferromagnetic order as in pure NdB6 first occurs at TN , then coexists with an incommensurate component below the lower transition temperature. These results are in good agreement with previous resistivity measurements and support the idea that Ce and Nd magnetic moments in this system can be relatively decoupled.

The extraordinary Hall effect is a sensitive probe of conduction-electron scattering in heavy-fermion systems. In CeRu2Si2, the large positive maximum of the Hall constant RH(T) (measured for i⊥H⌈c-axis) that occurs at Tmax = 18K at ambient pressure shifts rapidly to higher temperatures as P increases, reflecting the rise of the characteristic spin-fluctuation energy. At low pressures, the Hall voltage displays a pronounced peak as a function of H, corresponding to the metamagnetic-like transition of the material, and its critical field increases rapidly with pressure. Above ≅5 kbar, a broad maximum occurs around 5 T, suggesting that the system has crossed over into a mixed-valence state similar to that of, e.g., CeSn3.

The increasing frequency of EP and the need for its early diagnosis have focused our interest on the research of biochemical markers. We have established hormonal values in the plasma of 99 spontaneous ongoing pregnancies between the 4th and 10th weeks of amenorrhea, in 21 EPs, and 20 cases of early abortion. We have examined the predictive values of trophoblastic and CL production in pathological pregnancies. The association of low hCG and low active renin appears to be able to discriminate between ectopic and abortive spontaneous gestations.

Resume. Depuis quelques annees, on assiste dans tous les centres de neutrons a un regain d’interet pour les experiences realisees sous “conditions extremes”. En partant des techniques classiques de basses temperatures, forts champs et hautes pressions adaptees a la diffusion neutronique, ce cours passe en revue les developpements en cours ou a venir, depuis les echantillons microscopiques etudies dans les cellules a enclumes en diamant jusqu’aux puissantes installations devant produire des champs magnetiques bien superieurs a la limite actuelle des 15 teslas.

The structure of transition metal trichalcogenides is made up of infinite chains of atoms in the center of trigonal prisms stacked on the top of each other. Depending on the effective coupling between chains, this family of compounds is well suited to exhibit properties which extend from pseudo one-dimensionality to anisotropic three dimensionality. Nb-Nb pairs makes NbS3 a semiconductor ; TaS3 exhibits a metal-insulator transition due to a Peierls distorsion at 210 K. TaSe3 is superconductor below 2.1 K and NbSe3 undergoes two independant CDW transitions at 145 K and 59 K. The resistivity anomalies associated with the CDWs formation in NbSe3 have been shown to be strongly nonlinear with the applied current. We summarize several theoretical models to explain these striking properties. NbSe3 exhibits also two others transitions at 2.2 K and around 0.6 K. The resistivity drops below 2.2 K by 30 to 75 % of its residual value at 4.2 K and reaches a plateau. Below 0.4 K the resistivity decreases linearly down to 7 mK. Initial susceptibility measurements down to 50 mK do not show any increase in diamagnetism indicating flux expulsion. However NbSe3 is a bulk superconductor under pressure. We discuss the nature of these low temperature transitions with the eventual occurence of superconductivity.

Endothelins exhibit growth regulating properties in many cell types, and there is now considerable evidence that they play a critical pathophysiological role in human diseases such as carcinogenesis. In the choriocarcinoma cell lines JEG-3, JAR and BeWO, we demonstrate by RT-PCR that prepro endothelin (ET)-1 and prepro ET-2 mRNA were expressed, whereas prepro ET-3 was never expressed. Only ET-1 and ET-2 peptides were identified by HPLC/RIA analyses in culture media from these three choriocarcinoma cell lines. In the BeWO line, the cellular growth measured as the cell count and DNA content decreased with increasing concentrations of dimethyl sulfoxide (DMSO; range 0.5-3%). The expression of prepro ET-2 was also suppressed by DMSO, whereas no change was noticed inprepro ET-1 mRNA. All these effects were reversible when DMSO was replaced by 15% foetal calf serum. These effects of DMSO which are correlated to ET-2 down regulation in dividing BeWO cells suggest a role for this endothelin isoform in trophoblast proliferation.

We have studied the effect of Lu substitution on the spin dynamics of the Kondo insulator YbB12 to clarify the origin of the spin-gap response previously observed at low temperature in this material. Inelastic neutron spectra have been measured in Yb1-xLuxB12 compounds for four Lu concentrations x = 0, 0.25, 0.90 and 1.0. The data indicate that the disruption of coherence on the Yb sublattice primarily affects the narrow peak structure occurring near 15-20 meV in pure YbB12, whereas the spin gap and the broad magnetic signal around 38 meV remain almost unaffected. It is inferred that the latter features reflect mainly local, single-site processes, and may be reminiscent of the inelastic magnetic response reported for mixed-valence intermetallic compounds. On the other hand, the lower component at 15 meV is most likely due to dynamic short-range magnetic correlations. The crystal-field splitting in YbB12 estimated from the Er3+ transitions measured in a Yb0.9Er0.1B12 sample, has the same order of magnitude as other relevant energy scales of the system and is thus likely to play a role in the form of the magnetic spectral response., Comment: 16 pages in pdf format, 9 figures. v. 2: coauthor list updated; extra details given in section 3.2 (pp. 6-7); one reference added; fig. 5 axis label changed

The status of the corticosteroid-binding globulin (CBG) at the fetomaternal interface, especially in the maternal intervillous blood space (I), was investigated and compared to that of CBG in the maternal (M) and fetal (umbilical arteries [A] and vein [V]) peripheral circulations at term. Immunoquantitation of plasma CBG showed that the CBG concentration in I was 30% less than that in M (P0.001) and threefold higher than that in umbilical cord blood (P0.001). The microheterogeneity of CBG studied by immunoaffinoelectrophoresis in the presence of concanavalin A and Western blotting indicated that the CBG in I was mainly of maternal origin and different from fetal CBG. A CBG mRNA, but no classic 50- to 59-kDa CBG, was found in isolated term trophoblastic cells. The steroid environment of the CBG in I differed greatly from that in the peripheral maternal and fetal circulations, because the progesterone:cortisol molar ratio in I was 75-fold higher than that in M and 7- to 10-fold higher than that in the fetal circulation. Binding studies revealed that the affinity constants of CBG for cortisol in I, A, and V were significantly lower than that in M plasma (P0.02) in their respective hormonal contexts. The binding parameters for I-CBG stripped of endogenous steroids and lipids were close to those for M-CBG but different from those of fetal CBG (P0.001). These data reflect the physiological relevance of the CBG-steroid interaction, especially with very CBG-loaded progesterone at the fetomaternal interface during late pregnancy.

Inelastic neutron scattering measurements of magnetic excitations in the charge-ordered state of Yb4As3 have been performed under magnetic field up to about 6 T. By applying a magnetic field, the spectrum at the one-dimensional wave vector q = 1 [ pi/d] changes drastically from a broad one corresponding to the spinon excitation continuum of the one-dimensional S = 1 / 2 spin system to a sharp one at a finite energy, indicating the opening of an energy gap in the system. The magnetic field dependence of the gap is well fitted by the power law H2/3. The experimental result gives strong evidence for the existence of a staggered field alternating along Yb3+ chains induced by the Dzyaloshinsky-Moriya interaction.

The presence of progesterone receptors (PR) throughout the human term fetoplacental vascular tree was investigated. By reverse transcription-polymerase chain reaction (RT-PCR), we showed expression of PR mRNAs in stem villi vessels, chorionic arteries and veins, and umbilical arteries and veins. Binding studies and Scatchard analysis revealed a single class of high-affinity binding sites for (3)H-R5020 (promegestone) in cytosolic extracts of all placental vessels, with K(d) values in the range of 2.5-4 nM. High levels of PR were detected in placental vessels compared to other vascular tissues. Thus, maximum binding capacities of stem villi vessels, chorionic arteries and veins, and umbilical arteries and veins were 247 +/- 25, 377 +/- 58, 295 +/- 40, 371 +/- 118, and 672 +/- 144 fmol/mg protein, respectively. Endothelial cell elimination in chorionic arteries did not significantly modify the number of PR. RT-PCR and binding studies also assessed PR expression in cultured placental vascular smooth muscle cells isolated from stem villi vessels. All these data suggested that most of the PR of fetoplacental vessels were from the media. In conclusion, we report here the first evidence of the presence of PR in the muscular layer of human term fetoplacental vessels. This finding, together with the high progesterone concentrations in cord blood, suggests that the interactions between the PR and its ligand may play a role in the physiology and physiopathology of human fetoplacental vascularization.

Polyunsaturated fatty acids (PUFA) like arachidonic (C20:4) and docosahexaenoic (C22:6) acids are essential for harmonious fetal development. This study evaluates, at near term, the distributions of free fatty acids (FFA) and their fetal carrier protein, alpha-fetoprotein (AFP) in the maternal (M) and fetal circulation (umbilical arteries (A) and vein (V)), focusing on the feto-material interface where maternal intervillous blood (I) contacts the fetal trophoblast. FFA concentrations in intervillous and maternal blood were similar, while those in umbilical arteries and vein were 2- to 4-fold lower (P0.001). There were more saturated FFA in umbilical vein (41%) and arteries (44%) blood than in maternal (30%) and intervillous (32%) blood (P0.001). Monounsaturated FFA predominated (P0.001) in maternal (43%) blood, but not in intervillous (35%), umbilical vein (33%) and arteries (31%) blood. Di-triunsaturated FFA were similar in intervillous and maternal (25%) blood and lower in umbilical vein and arteries (16%) (P0.001). PUFA were low in maternal (2.5%) blood and higher in intervillous and umbilical vein and arteries (9%, P0.001); consequently, C20:4 (40 microM) and C22:6 (16 microM) were the most abundant in the intervillous space. The AFP concentrations and AFP lectin-reactive isoforms were similar in intervillous and umbilical vein and arteries blood, but immuno-electrophoresis revealed a particular AFP conformation (less immuno-reactive, more anionic) in the intervillous space, suggesting that AFP is heavily loaded with PUFA at the feto-maternal interface. Prostacyclin derived from C20:4 was similar in all compartments but the thromboxane A2 concentration was 10-fold higher in intervillous blood than in maternal and umbilical vein and arteries blood. Thus the feto-maternal interface has a specific pattern of cell signalling molecules that might critically influence parturition.

The authors describe a case of percutaneous extraction of a piece of silicone-coated catheter, 5 years after its embolisation in the pulmonary artery and the results of electronic microscopic study of the specimen. The discussion provides the factors indicating extraction which is relatively easy with this technique irrespective of the chronicity of embolisation, in order to avoid infectious complications.

We report inelastic neutron scattering results for single-crystalline samples of PrFe 4 P 12 , which undergoes a transition from the heavy-electron phase to the antiferro-type nonmagnetic ordered phase. In contrast to the quasielastic magnetic response observed in the heavy electron phase, the well-defined inelastic peaks located at 1.5 and 3 meV are superimposed in the ordered phase. The maximum spectral intensity appears at the Brillouin zone center for the original I m \bar3 structure, and the minimum spectral intensity appears at the zone boundaries including the ordering vector q 0 =(1,0,0). The evolution of the 1.5 meV peak with an applied magnetic field in the ordered phase is in agreement with excitations between 4 f -electron crystalline-field-splitting levels, while the 3 meV peak is smeared out rapidly. The spectra are consistent with the recently proposed staggered ordering of a Pr site with well-localized f -electrons and that with a Kondo-singlet-like state, which are represented as the tota...

The magnetic phase diagrams of hexagonal R2PdSi3 compounds have been found to feature an apparent similar phase when the field is applied along the respective magnetic easy axes. To elucidate this, neutron diffraction on single crystalline Tb2PdSi3 and Ho2PdSi3 in magnetic fields was performed. These two compounds have different magnetic structures in zero field. In Tb2PdSi3 the propagation vector is parallel to the hexagonal axis while in Ho2PdSi3 the propagation is in the basal plane. In both compounds the magnetic moment direction is perpendicular to the propagation vector. The application of a magnetic field along the respective easy axes destroys the zero field magnetic structure and leads to a ferrimagnetic phase with magnetic intensity on the same positions for both compounds. These findings and their connections to the crystallographic (super-)structure are presented and discussed.

The 84.3 keV Mossbauer transition in170Yb was used to investigate the intermediate valent intermetallic compound YbCuAl at pressures up to 130 kbar and in the temperature range between 1.6 K and 77 K. The electric quadrupole interaction parameters |eQVzz| and η, as well as their temperature variation are drastically dependent on pressure: |eQVzz| is at 4.2 K larger by almost a factor of three at 130 kbar when compared to ambient pressure. On the other hand, |eQVzz| drops by more than a factor of two at 130 kbar when the temperature is raised from 1.6 K to 77 K. A much smaller temperature dependence of quadrupole coupling is present at ambient pressure. Both these effects give strong evidence for a valence transition towards the 4f13 (Yb3+) configuration under applied pressure. At 4.2 K this transition is completed near ∼50 kbar. No magnetic order could be detected down to 1.6 K over the whole pressure range. Some line broadening is observed at high pressures and low temperatures which most probably is related to paramagnetic relaxation phenomena and supports the claim that the Yb ion is in a magnetic state under these conditions.

Eggs of Emys orbicularis L. were incubated at either 25° (100% male-producing temperature) or at 30° (100% female-producing temperature). Gonadal levels of seven steroids were subsequently measured in embryos (stage 24), hatchlings, and young (3 and 9 months). According to the stage, 22–80 gonads were first removed and cultured in synthetic medium for 2 hr. They were then pooled and homogenized in this medium for steroid assay (RIA). The total steroid levels were weak (10–30 pg/gonad) in embryos and hatchlings and increased in the young turtles. In embryos, total steroid level was higher in males than in females, while at 9 months it was higher in females. As for the different steroids, the main following results were obtained. In embryos, progesterone (Prog), dehydroepiandrosterone (DHA), and testosterone (Testo) were not detected in either testes at 25° or ovaries at 30°, while Δ4-androstenedione (Δ4A), dihydrotestosterone (DHT), and estrone (E1) were found in higher levels in testes (chiefly E1). Low levels in testes or traces in ovaries of estradiol (E2) were present. At hatching, E2 was no longer detectable, while DHA in both sexes and Testo in males were measurable. At this time, the other hormones displayed either minor variations in females or were decreased in males. At 3 months, Prog and E2 were still missing and only traces of E1 were detected. DHA decreased in males, while it increased in females. Levels of the other steroids, mainly Testo (in both sexes) and DHT (in males) increased. At 9 months, all steroids except E2 were detected. The total steroid content increased markedly, with the highest levels being found for Prog and Δ4A, chiefly in ovaries. This latter increase could be related to the posthatching differentiation of interstitial gland (Leydig cells) in testes and to follicle growth in ovaries.

An extensive study of the spin dynamics in the strongly correlated semiconductors YbB 12 and SmB 6 , as well as in the series of related electron-doped systems, has been performed by means of inelastic neutron scattering spectroscopy. It was found that rare-earth compounds with a valence instability may develop an exciton-like in-gap excitation, generally similar to the so-called resonant mode initially discovered in HTSC. The results of this work, along with the literature data for a number of high- T c -, heavy-fermion- and pnictide superconductors and some magnetic compounds point to such type of resonant excitations being characteristic for systems with gap-like dynamical response in the presence of competing interactions . The correlation between the temperature evolutions of the resonant mode and of the gap in the excitation spectrum is discussed.

Since the compounds TmS and TmSe have been reported to exhibit unstable valence states1,2, a lot of experimental work has been devoted to some unusual features of their low temperature properties. It seems now well established that Tm3+ induced-moment ordering occurs in both of these singlet ground state systems in the liquid helium temperature range. However, the local moment induced on the thulium ions cannot be obtained simply from a magnetization measurement since an external field changes not only its orientation but also its absolute value.

In 15 cynomolgus monkeys between days 30-160 of gestation, tissue levels of oestrone (E1), oestradiol 17 beta (E2) and progesterone (P4) were assayed by RIA in the myometrium and the placenta. Myometrial samples were subdivided as follows: inner and outer layers adjacent to the placental area (IMP and OMP) and inner and outer layers from antiplacental areas (IMAP and OMAP). Steroid levels (ng/g wet wt) were in the range of known plasma values (ng/ml) and there was no asymmetric distribution of steroids between the various locations. When the results obtained in all the layers were pooled the gestational profiles indicated a decrease of E1 between days 80-130, whereas at the same time E2 and P4 increased. The ratio P4/E2 was 8 on day 40, 17 on day 80 and 9 on day 160. In the placenta, levels of E2 and P4 were 4 times higher, levels of E1 10 times higher than in the myometrium. Gestational profiles of the three steroids in the placenta increased from day 30 to day 160. Myometrium steroid content therefore does not appear to be a simple reflection of steroid diffusion from the site of production.

We describe SQUID susceptibility measurements on several dilute natural and monoisotopic Au Yb alloys down to 7 mK. Whereas Au 174Yb obeys a Curie‐law in the whole range of temperature, a very unusual case of a Van‐Vleck‐like behavior due to an electro‐nuclear singlet ground‐state is reported for Au 171Yb. This peculiar situation also results in a Schottky anomaly centered at 45 mK, which is observed in specific heat measurements down to 25 mK.

Quail embryos with a sex-linked eye pigmentation marker allowing sex identification at autopsy provided a biological model for radioimmunoassay of sex steroids in embryonic quail gonads at a very early stage ( 5 1 2 and 6 1 2 days ). The purpose was to demonstrate a sex difference in hormonal potentialities of the gonads before any morphological indication of sexual differentiation. Evidence of early steroidogenesis by undifferentiated gonads could be obtained: estrogen synthesis characterized female gonads, while testosterone was produced by the gonads of both sexes. The sex hormonal production was concomitant with, or even preceded, the apparent beginning of sex differentiation of gonads.

Prorenin (PR) an inactive high molecular weight form of renin normally circulates in human plasma at a concentration of about 10 times that of active renin (AR) and this proenzyme seems to be linked to the reproductive function. It has been demonstrated that AR and PR are present at high concentrations in follicular fluid when the ovaries are stimulated with gonadotropins and that the PR plasma levels increase steadily after hCG injection with a correlation between blood PR and the number of developing follicles and corpora lutea. From September 1986 we studied the profile of immunoreactive active renin (AR) and prorenin (PR) in plasma during hyperstimulated cycles for IVFET or GIFT. All women were treated with a protocol combining GnRH analog (Decaptyl Ipsen Biotech, Paris France) and human menopausal gonadotropins until injection of 5,000 IU hCG. AR has been assayed in frozen samples by specific immunoradiometry (Renin RIA code 79 795, Pasteur Diagnostic, France) using two complementary monoclonal antibodies. A second assay of total renin was carried out after trypsin activation which revealed the inactive form. Progesterone (P), estradiol (E2) were measured by radioimmuno-assays. During the follicular phase, from day 1 of hMG administration to the day before hCG, no significant difference could be found between two groups, 63 pregnant or 60 nonpregnant cycles matched for age and number of oocytes retrieved, for E2, P, PR and AR. During the periovulatory period (D - 1, Do = day of hCG injection and D 1) no difference could be found for E2, P and PR (tabl. 1). In the 2 groups the mean E2 levels increased after hCG injection, as well as P and PR. But a significant difference appeared for AR which increased in the plasma immediately after hCG administration in the pregnant group whereas it decreased in the non-pregnant group (+2.5 vs -2 pg/ml) the mean variation between Do and D + 1 being significantly different in fertile cycles and in nonfertile cycles.(ABSTRACT TRUNCATED AT 400 WORDS)

The degree of lymphocyte infiltration in subtotal thyroidectomy specimens from patients with treated Graves' disease varies greatly from one case to another. A morphometric study, employing standard and immunofluorescent slides was conducted to evaluate possible statistical correlations between clinical and morphological findings. Quantitative lymphoplasmocytic cellularity differences appeared to be related to the course of the disease. Lymphocyte infiltration was greater in patients with long-standing disease and/or relapses.

Embryonic gonads from White Leghorn chick embryos 7.5–18 days old were cultured on synthetic medium for 24 hr. Radioimmunoassys after ether extraction of the homogenized organs and their corresponding media allowed us to determine qualitatively and quantitatively the amount of secreted steroids. Steroid production by the explant is confirmed because the relative amount of each steroid present in the cultures (explants + media) is higher than the initial hormonal content of the gonads before explanation. Estradiol (E2), testosterone (T), and dehydroepiandrosterone (DHA) are mainly found in the culture media, whereas progesterone (P), DHA, and estrone (E1) remain more or less in the gonads. Total steroid production increases during development for gonads of both sexes, with significant higher levels in females. A preferential relative production according to the sex is obvious. The absolute or relative production of estrogens (E1 + E2) is always more abundant in female gonads than in male gonads. For testosterone, the production by pairs of gonads is higher in females than in males until 15 days, after which it is the contrary. The relative secretion is higher in males and shows a maximum value at 10 days which may be correlated with the regression of the Mullerian ducts. TE2 is always > 1 in testes and < 1 in the left ovary, but in right female gonads it reaches 1.61 at 10 days of incubation. DHT is mainly secreted by male gonads and also shows a peak at 10 days. For female gonads, a quantitative as well as a qualitative difference in steroid secretion appears between left and right gonads; these latter, even though fated to rudimentation, are not devoid of steroidogenic capability.

The authors describe the possibility of an anomaly of the plica synovialis in cases of patellar pain and disturbance of function on the medial sides of the knee. A diagnosis is bases on the study of arthrography, associated with patello-femoral views. Thirteen knees have been operated on; the types of lesions of the synovial plicae and possible associated lesions of the patellar cartilage are described.

Pregnancy-associated plasma protein-A (PAPP-A), a macromolecular glycoprotein of placental origin, was reported to be depressed in established ectopic pregnancies. CA 125 is a known marker for ovarian cancer found to be elevated during the first trimester of pregnancy and in women with pelvic inflammatory disease. The present study investigated the usefulness of these parameters to predict the outcome of pregnancy in asymptomatic patients with a positive pregnancy test after in-vitro fertilization and embryo transfer (IVF-ET). Blood samples (n = 159) were obtained at different periods of time post-ET from 39 women, 21 of whom experienced a normal pregnancy, 12 had an intrauterine abortion and six had an ectopic pregnancy. PAPP-A and CA 125 were measured by radioimmunoassays. From day 30 onwards in normal pregnancies, PAPP-A was significantly increased over non-pregnant controls. In the spontaneous abortion group, the levels of PAPP-A were significantly lower than in normal pregnancy but higher than in non-pregnant controls. In ectopic pregnancy, PAPP-A remained at the level of non-pregnant controls throughout the entire observation period. CA 125 was significantly increased in all types of pregancy. However, in two cases of hyperstimulation followed by a normal pregancy and in four cases of ectopic pregnancy with signs of peritoneal irritation (hydrosalpinx, ruptured ectopic or salpingitis) the levels of CA 125 were 15-50 times higher than in normal pregnancies. PAPP-A levels < 10th percentile, measured after 30 days post-ET, were an excellent diagnostic parameter for ectopic pregnancy or intrauterine abortion with a sensitivity of 87.5% and a predictive value of disease of 100%. In contrast, CA 125 determinations had no diagnostic value and were only indicative of peritoneal inflammation in either normal or pathological pregnancies. It is concluded that PAPP-A is a good parameter by which to monitor post-implantation viability of embryos in IVF-ET patients

Magnetoresistance measurements on Ce1−xLaxRu2Si2 single crystals are reported. For x = 0.05 a maximum of ϱ is observed at the metamagnetic-like transition field as in CeRu2Si2. In the AF-ordered alloys, ϱ(H) is always negative above TN, while below TN it drops at the magnetic transitions and reproduces their hysteresis effects.