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Resumen: Introducción y objetivos: La cirugía bariátrica es el mejor método contra la obesidad y sus comorbilidades. El objetivo fue analizar detalladamente los resultados perioperatorios y la evolución de pacientes latinos sometidos a cirugía en un centro de alto volumen. Material y métodos: Estudio retrospectivo, con todos los pacientes sometidos a cirugía bariátrica en un solo centro, durante 4 años y medio. Se realizó análisis demográfico, perioperatorio, de complicaciones (tempranas y tardías), pérdida de peso, falla y remisión de diabetes mellitus tipo 2. Resultados: Se incluyeron 500 pacientes, un 83.2% mujeres, con edad media de 38.8 años e IMC de 44.1 kg/m2. Las comorbilidades mayormente observadas fueron hipertensión, dislipidemia y diabetes. Se realizó bypass gástrico laparoscópico en el 85.8%, manga gástrica en el 13% y cirugía revisional en el 1%. Hubo un 9.8% de complicaciones tempranas y un 12.2% de tardías, sin mortalidad. La pérdida de peso global en porcentaje de exceso de peso perdido a 12 y 24 meses fue del 76.9% y 77.6%; el BPGL tuvo mayor pérdida de peso a los 12 meses. La falla al tratamiento fue del 11.4%. En los pacientes con DM2 existió remisión completa en el 68.7%, remisión parcial en el 9.3% y una mejoría en el 21.8% de los casos. Conclusiones: En nuestra experiencia como centro de alto volumen, la cirugía bariátrica es segura y efectiva basada en el bajo número de efectos adversos, y la pérdida de peso con control de la DM2. Estudios a largo plazo y con un mayor número de pacientes son necesarios para determinar el impacto final de dichos procedimientos. Abstract: Introduction and objectives: Bariatric surgery is the best method for treating obesity and its comorbidities. Our aim was to provide a detailed analysis of the perioperative outcomes in Mexican patients that underwent surgery at a high-volume hospital center. Materials and methods: A retrospective study was conducted on all the patients that underwent bariatric surgery at a single hospital center within a time frame of 4 and one-half years. Demographics, the perioperative variables, complications (early and late), weight loss, failure, and type 2 diabetes mellitus remission were all analyzed. Results: Five hundred patients were included in the study, 83.2% of whom were women. Mean patient age was 38.8 years and BMI was 44.1 kg/m2. The most common comorbidities were high blood pressure, dyslipidemia, and diabetes. Laparoscopic gastric bypass surgery was performed in 85.8% of the patients, sleeve gastrectomy in 13%, and revision surgeries in 1%. There were 9.8% early complications and 12.2% late ones, with no deaths. Overall weight loss as the excess weight loss percentage at 12 and 24 months was 76.9 and 77.6%. The greatest weight loss at 12 months was seen in the patients that underwent laparoscopic gastric bypass. A total of 11.4% of the patients had treatment failure. In the patients with type 2 diabetes mellitus, 68.7% presented with complete disease remission and 9.3% with partial remission. There was improvement in 21.8% of the cases. Conclusions: In our experience at a high-volume hospital center, bariatric surgery is safe and effective, based on the low number of adverse effects and consequent weight loss and type 2 diabetes mellitus control. Long-term studies with a larger number of patients are needed to determine the final impact of those procedures. Palabras clave: Cirugía bariátrica, Bypass gástrico laparoscópico, Manga gástrica laparoscópica, Complicaciones, Remisión de diabetes, Cirugía de obesidad, Keywords: Bariatric surgery, Laparoscopic gastric bypass, Laparoscopic sleeve gastrectomy, Complications, Diabetes remission, Obesity surgery

Introduction and objectives: Bariatric surgery is the best method for treating obesity and its comorbidities. Our aim was to provide a detailed analysis of the perioperative outcomes in Mexican patients that underwent surgery at a high-volume hospital center. Materials and methods: A retrospective study was conducted on all the patients that underwent bariatric surgery at a single hospital center within a time frame of 4 and one-half years. Demographics, the perioperative variables, complications (early and late), weight loss, failure, and type 2 diabetes mellitus remission were all analyzed. Results: Five hundred patients were included in the study, 83.2% of whom were women. Mean patient age was 38.8 years and BMI was 44.1 kg/m2. The most common comorbidities were high blood pressure, dyslipidemia, and diabetes. Laparoscopic gastric bypass surgery was performed in 85.8% of the patients, sleeve gastrectomy in 13%, and revision surgeries in 1%. There were 9.8% early complications and 12.2% late ones, with no deaths. Overall weight loss as the excess weight loss percentage at 12 and 24 months was 76.9 and 77.6%. The greatest weight loss at 12 months was seen in the patients that underwent laparoscopic gastric bypass. A total of 11.4% of the patients had treatment failure. In the patients with type 2 diabetes mellitus, 68.7% presented with complete disease remission and 9.3% with partial remission. There was improvement in 21.8% of the cases. Conclusions: In our experience at a high-volume hospital center, bariatric surgery is safe and effective, based on the low number of adverse effects and consequent weight loss and type 2 diabetes mellitus control. Long-term studies with a larger number of patients are needed to determine the final impact of those procedures. Resumen: Introducción y objetivos: La cirugía bariátrica es el mejor método contra la obesidad y sus comorbilidades. El objetivo fue analizar detalladamente los resultados perioperatorios y la evolución de pacientes latinos sometidos a cirugía en un centro de alto volumen. Material y métodos: Estudio retrospectivo, con todos los pacientes sometidos a cirugía bariátrica en un solo centro, durante 4 años y medio. Se realizó análisis demográfico, perioperatorio, de complicaciones (tempranas y tardías), pérdida de peso, falla y remisión de diabetes mellitus tipo 2. Resultados: Se incluyeron 500 pacientes, un 83.2% mujeres, con edad media de 38.8 años e IMC de 44.1 kg/m2. Las comorbilidades mayormente observadas fueron hipertensión, dislipidemia y diabetes. Se realizó bypass gástrico laparoscópico en el 85.8%, manga gástrica en el 13% y cirugía revisional en el 1%. Hubo un 9.8% de complicaciones tempranas y un 12.2% de tardías, sin mortalidad. La pérdida de peso global en porcentaje de exceso de peso perdido a 12 y 24 meses fue del 76.9% y 77.6%; el BPGL tuvo mayor pérdida de peso a los 12 meses. La falla al tratamiento fue del 11.4%. En los pacientes con DM2 existió remisión completa en el 68.7%, remisión parcial en el 9.3% y una mejoría en el 21.8% de los casos. Conclusiones: En nuestra experiencia como centro de alto volumen, la cirugía bariátrica es segura y efectiva basada en el bajo número de efectos adversos, y la pérdida de peso con control de la DM2. Estudios a largo plazo y con un mayor número de pacientes son necesarios para determinar el impacto final de dichos procedimientos. Keywords: Bariatric surgery, Laparoscopic gastric bypass, Laparoscopic sleeve gastrectomy, Complications, Diabetes remission, Obesity surgery, Palabras clave: Cirugía bariátrica, Bypass gástrico laparoscópico, Manga gástrica laparoscópica, Complicaciones, Remisión de diabetes, Cirugía de obesidad

Bariatric surgery is the most effective treatment for weight loss, with comorbidity control. With low complication rates, the reasons for reoperation are major complications or weight loss failure/weight regain. Nonsurgical problems can also present, such as anemia, dehydration, chronic pain, and malnutrition, among others. Our aim was to analyze the main causes of revisional surgery, reoperation, and hospital readmission, at a specialized bariatric center.A retrospective study was conducted on patients that underwent bariatric surgery within the time frame of 2012 and 2019. The baseline analysis included demographic, anthropometric, and perioperative data, as well as a sub-analysis of the main readmission causes and complications.A total of 776 primary surgeries were performed (649 RYGBP, 127 SG, and 10 revisional surgeries), and 99 patients were identified for the study: 10 revisional surgeries, 44 reoperations, and 45 readmissions. The incidence of revisional surgery was 1.2%, reoperation was 5.6%, and readmission 5.8%. Fifty percent of the revisional surgeries were performed due to insufficient weight loss or weight regain; the most frequent causes of reoperation were cholecystitis (38.6%) and internal hernias (9.1%); and the most common causes of readmission were nonspecific abdominal pain (35.5%) and dehydration (24.4%).The most frequent causes of postoperative readmission were nonsurgical events, followed by non-bariatric reoperations, and finally revisional surgeries. There was a low incidence of early reoperations. Knowledge of the abovementioned data is important for identifying higher-risk patients, to prevent major complications.

BackgroundAutoantibodies (Aab) are frequent in systemic sclerosis (SSc) [1]. Recently, it has been showed that immunoglobulins G (IgG) from SSc promoted proinflammatory and profibrotic phenotype in monocyte secretome [2]. Fibroblasts (FB) are key effectors cells in SSc and data on FB proteins secretion in the presence of IgG from SSc patients are lacking. While recognized as potent biomarkers, the pathogenic role of Aab is much more debated.ObjectivesTo explore the FB secretome in the presence of purified IgG from SSc patientsMethodsNormal dermal FB were cultured in the presence of purified IgG from patients with diffuse cutaneous SSc (dcSSc), limited cutaneous SSc (lcSSc) or healthy controls (HC). After 72 h of culture, the cell supernatants were collected, centrifuged and passed through a filter to remove the cells. After proteins digestion, secretome was explored using mass spectrometry coupled with liquid chromatography (LC-MS/MS). Analysis of variance (ANOVA) and hierarchical clustering were used to identify proteins responses patterns.ResultsProteomic identified and quantified 1268 proteins, among them 377 were significant after ANOVA. SSc and HC secretome appeared distinct. Hierarchical clustering on significant proteins after ANOVA showed 3 distinct groups of patients secretome: a first group including mostly dcSSc anti-topoisomerase-I (ATA) positive (dcSSc ATA+) patients, a second group including mostly dcSSc ATA negative (dcSSc ATA-) patients, a third group more heterogeneous including the majority of HC, lcSSc anti-centromere positive (lcSSc ACA+) patients and dcSSc ATA- patients (Figure 1.A). The comparison of FB secretome in the presence of purified IgG from dcSSc ATA+ vs IgG HC revealed 203 differentially expressed proteins (DEP) (Figure 1.B). The enriched Gene Ontology (GO) terms upregulated in IgG dcSSc ATA+ were involved in endocytic vesicle lumen, vesicle lumen, extracellular matrix or glycosaminoglycan binding. The comparisons of IgG dcSSc ATA- vs IgG HC and IgG lcSSc ACA+ vs IgG HC revealed 85 and 15 DEP, respectively. Follistatin, amyloid beta A4 protein, myosin-9 and calreticulin were commonly overexpressed in the 3 subtypes of SSc. 40 proteins were exclusively overexpressed in the condition dcSSc ATA+. Among them, collagen alpha-1(VII) chain, galectin-3-binding protein, desintegrin and metalloproteinase domain-containing 10, low affinity immunoglobulin gamma Fc region receptor III-A, CD59 glycoprotein, growth arrest-arrest specific protein and clusterin were overexpressed in the condition dcSSc ATA+ (Figure 1.C).Figure 1.Heatmap representing the 377 differentially expressed proteins after ANOVA in all samples. Cluster analysis identified 3 group of patients and 2 different clusters of protein expression (A). Volcanoplot represented the comparison IgG dcSSc ATA+ vs IgG HC (B). Venn diagram representing the proteins in common and exclusive of the following comparison: IgG dcSSc ATA+ vs HC, IgG dcSSc ATA- vs IgG HC and IgG dcSSc ATA- vs IgG HC (C). IgG HC: purified IgG from healthy controls; IgG dcSSc ATA+: purified IgG from diffuse systemic sclerosis anti-topoisomerase-I positive patients; IgG dcSSc ATA-: purified IgG from diffuse systemic sclerosis anti-topoisomerase-I negative patients; IgG lcSSc ACA+: purified IgG from limited systemic sclerosis anti-centromere positive patients. ANOVA: analysis of variance.ConclusionUsing sensitive proteomic approach, we identified that purified IgG from SSc patients modified FB secretome in a serotype dependent manner. The data support the pathogenic role of Aab in SSc.References[1]Denton CP, Khanna D. Systemic sclerosis. The Lancet 2017; 390:1685–99. doi:10.1016/S0140-6736(17)30933-9[2]Murthy S, Wannick M, Eleftheriadis G, et al. Immunoglobulin G of systemic sclerosis patients programs a pro-inflammatory and profibrotic phenotype in monocyte-like THP-1 cells. Rheumatology (Oxford) 2021; 60:3012–22. doi:10.1093/rheumatology/keaa747Disclosure of InterestsNone declared.

Introduction Type 2 diabetic women are at greater risk of cardiovascular (CV) diseases than men, but the mechanisms involved are still poorly understood. Objective The objective of this study was to investigate the effect of sex on the myocardial tolerance to ischemia-reperfusion (IR) injury in type 2 diabetic Goto-Kakizaki (GK) rats. Method We performed ex vivo experiments on isolated perfused hearts to evaluate tolerance to IR injury of male and female GK and Wistar rats. We simultaneously measured energy metabolism by 31P magnetic resonance spectroscopy, myocardial function and coronary flow. At the end of the experiments, biochemical analyses were performed on plasma and hearts. Results GK rats had cardiac hypertrophy and higher glycemia than control rats, without effect of sex. Basal oxidative stress was significantly higher only in female GK rats in comparison to other groups, with higher plasmatic level of 8-iso-PGF2α. Male and female GK rats had impaired cardiac function before and after IR injury in comparison to respective controls. Interestingly, female GK rats had greater impairment of cardiac function than male GK during reperfusion, associated with decreased ATP and PCr level, and higher impairment of coronary flow. Biochemical analyses in hearts showed downward trend in SIRT1 expression in GK rats versus control groups, without sex-effect. Citrate synthase activity and SIRT3 protein expression were similar between groups. Conclusion These results indicate that sex influences the myocardial tolerance to IR injury in type 2 diabetes. Mitochondrial and endothelial dysfunction might explain why female GK have lower myocardial function during reperfusion. These results may be related to the higher risk of cardiovascular complications among type 2 diabetic women.

Bariatric surgery is the best method for treating obesity and its comorbidities. Our aim was to provide a detailed analysis of the perioperative outcomes in Mexican patients that underwent surgery at a high-volume hospital center.A retrospective study was conducted on all the patients that underwent bariatric surgery at a single hospital center within a time frame of 4 and one-half years. Demographics, the perioperative variables, complications (early and late), weight loss, failure, and type 2 diabetes mellitus remission were all analyzed.Five hundred patients were included in the study, 83.2% of whom were women. Mean patient age was 38.8 years and BMI was 44.1kg/mIn our experience at a high-volume hospital center, bariatric surgery is safe and effective, based on the low number of adverse effects and consequent weight loss and type 2 diabetes mellitus control. Long-term studies with a larger number of patients are needed to determine the final impact of those procedures.

le document est disponible en ligne : http://www.sciencedirect.com/science/article/pii/S1269176308001016; International audience; Cette recherche est orientée vers l’étude des activités tant professionnelles que privées des personnes, dans la perspective théorique du système des activités. Nous nous centrons sur la population des cadres en raison de la spécificité de leur rapport au temps de travail ainsi que du caractère flou des frontières qu’ils établissent entre le travail et le hors travail. De ces éléments découle une articulation complexe entre domaines de vie. La triangulation de trois méthodes (auto-observations, entretiens guidés par les auto-observations, protocoles ISA) permet d’obtenir des données riches et complémentaires et de réaliser quatre études de cas approfondies (trois femmes ayant 38, 46 et 51 ans, un homme ayant 38 ans). Les résultats mettent l’accent sur les déterminants multiples qui s’articulent en chaque personne, sur les différentes modalités de conciliation des activités de vie et enfin sur des perspectives de réflexion.

International audience; Photoluminescence related to the bound polaron Nb 4+Li is investigated as a function of temperature and incident light intensity in iron-doped lithium niobate crystals with various iron concentrations. Experiments are done under constant-wave (CW) and pulsed illumination. Its found that the decay time is always monoexponential. The radiative lifetime, the activation energy of the nonradiative lifetime and the quenching temperature are only weakly sensitive to iron concentration. On the other hand, the magnitude of the photoluminescence signal seems strongly correlated to the Fe2+ concentration, and the superlinear regime evidenced at low CW illumination definitely confirms that polaron excitation in lithium niobate is a two-step process.

The intensity, the peak wavelength and the decay time of polaron photoluminescence in congruent lithium niobate are measured versus temperature from 77 K to 290 K. The radiative relaxation shows quasi athermal behaviour (τR ≈ 9 µs) whereas the nonradiative relaxation follows arrhenius law with activation energy of 220 meV. The crossing point between radiative and nonradiative lifetimes is about 210 K. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The spectral widths of Raman lines in nominally pure lithium niobate are measured as a function of the cationic molar ratio, in a wide range from stoichiometry (50 mol% Li) to sub-congruent compositions (below 48.6 down to 47 mol% Li). The broadening observed on the sub-congruent side follows the same slopes as on the congruent-to-stoichiometric side. It is shown that micro-Raman analysis permits one to characterize short-range heterogeneities at the micron scale, such as growth striations in bulk crystals or lithium out-diffusion in the surroundings of titanium-diffused waveguides, with a typical accuracy of 0.04 mol%.

Deflection of light on a single domain wall in glycine phosphite crystal (GPI) was studied. The angular positions for all crossing the sample beams were measured as a function of the incidence angle ranged in 0 ± 40°. The angles of α o = α cri = 24.7° have been measured. The angular positions of all beams are in agreement with those calculated using the coordinate free method. Angular dependences of all output beam intensities were observed for two polarizations: the polarization along the high-index direction: (beams D B , R B ,A, and A′) and the polarization along the low-index direction: (beams D A , R A ,B, and B′). The experimental data show clearly the exchange of the intensities of the output beams appearing after crossing the sample containing one domain wall. Communicated by Prof. Bozena Hilczer et al.

Raman and luminescence spectroscopies are used for non destructive characterization of titanium-diffused LiNbO3 waveguides at the classical resolution of confocal microscopy (0.5×0.5×3 μm). The broadening of Raman lines near the surface permits one to measure the depths of lithium out-diffusion and titanium in-diffusion. The contrast of polaron luminescence makes it possible to control routinely the waveguides just after the diffusion process. Vertical scans give the thickness of the chemically-reduced layer near the surface of the wafer, whereas horizontal scans across the waveguides reveal screening effects by the titanium stripes against surface reduction.

Effect of external electric field and external mechanical stress influence on domain structure of RbHSeO4(RHSe) and NH4HSeO4 (AHSe) crystals was studied. Taking into account microscopic observations of domain structure in particular phases we consider the succesive changes of symmetry in this family as 222→2→1. It is in accordance with predictions of Aizu and Sapriel and the 222 is a symmetry of nonexisting prototype phase. The monoclinic phases are potentially ferroelectric and fully ferroelastic and the triclinic phases are fully ferroelastic and fully ferroelectric.

The variations of the effective electro-optic coefficient and of the dielectric permittivity as functions of the dc electric field are reported in rubidium hydrogen selenate at room temperature. Their frequency dispersions are measured in the range 20 Hz – 1 MHz. The influence of the ac field amplitude on these properties is also studied. It is shown that the dielectric and the electro-optic responses are strongly nonlinear with the amplitude of the ac electric field, and that their frequency dispersions are closely linked to one another, up to the vicinity of the piezoelectric resonances. The role of domain dynamics in the dielectric and electro-optic properties is stressed. The domain contribution to the electro-optic response is explained by means of a simple model based on the tilt of the optical indicatrix in neighboring domains.

The electronic and optical properties of stoichiometric lithium niobate are calculated from first principles within the Generalized Gradient Approximation (GGA). The band gap is found slightly indirect. Its value, underestimated by the GGA, is corrected on the basis of the refractive index by using our new approach called reverse scissor correction procedure. The corrected value (4.9 eV) is fairly comparable to previous ones obtained by GW calculation. The frequency dispersions of the dielectric function are re-calculated for different scissor corrections and compared to the experimental Sellmeier equation. A good agreement is obtained in the NIR-VIS-NUV range with our corrected band gap. The hopping integrals and effective masses at the extrema of the conduction and valence bands are also estimated.

International audience; The drift issue induces slow drifting of the optimum operating point for high efficiency or large nonlinearities in analog optical links, and requires complex control of the offset bias voltage for achieving high extinction ratio in digital optical links. We discuss and analyze the different sources of the drift in commercially LiNbO 3 Mach-Zehnder modulators. The different extrinsic and intrinsic origins are compared in terms of phase shift and the different corresponding orders of magnitude are given, pointing out the predominant role of the intrinsic (dc) drift. We show the large role played by the electrical inhomogeneities at the surface of the LiNbO 3 substrate by highlighting the link between the time dependence of the dc drift and the electrical conductivity measured at the surface and in the volume of the LiNbO 3 substrate. This allows to propose a solution to the drift issue which consists in the engineering of the electrical conductivity of the lithium niobate substrate.

Clinical and experimental evidence has indicated that the maternal immune response is biased toward antibody production and away from cell-mediated immunity during pregnancy, especially in the vicinity of the fetoplacental unit. Because antibody responses are often associated with the Th2 cytokine pattern, this suggests that Th2-type cytokines might predominate locally in the regulation of the maternal immune response. In order to test this hypothesis, we examined the local and distal release of cytokines during murine pregnancy using ELISA assays. We report here that the Th2-specific cytokines IL-4, IL-5, and IL-10 were readily detectable in cell supernatants derived from fetal-placental units in all three trimesters of gestation. IL-3 was also present. These cytokines were detected in lysates of freshly isolated, day 12 decidual and placental cells, and in supernatants as early as 15 min after the beginning of culture. The presence of functional IL-10 was confirmed by specific bioassay. IL-10 mRNA was localized to the decidua at day 6 of gestation by in situ hybridization. IFN-gamma was also found in the supernatants from the first trimester of pregnancy, but was barely detectable in the second, and undetectable in the third trimester. Cytokine expression was consistently detected in samples from individual mice. None of these cytokines was produced by unstimulated spleen or mesenteric lymph nodes from pregnant mice. IL-4, IL-10, and IFN-gamma were produced by Con A-stimulated spleen cells from virgin mice, but in ratios opposite to those found in the placenta. These observations indicate that Th2-specific cytokines are normally produced at the maternal-fetal interface. The continuous presence of IL-4, IL-5, and IL-10, with early and transient expression of IFN-gamma, can provide a molecular basis for the antibody/Th2-like bias of the maternal immune response during pregnancy.

Field-induced light deflection by ferroelectric domain walls in lithium niobate (LN) and lithium tantalate (LT) is theoretically studied. The phenomenon can occur not only when both the incident wave vector k and the electric field E are parallel to the z-axis—as demonstrated by experiments made so far—but also when E and/or k are perpendicular to z. In particular, for E parallel to x and k parallel to y, the deflection phenomenon is predicted to have the same characteristics as in triclinic or monoclinic ferroelastics: the large deflection angle is related to the natural birefringence, whereas the deflection amplitude is proportional to the small tilt angle of the neutral lines, which is here induced by the electric field. In periodic domain structures, interference between deflected waves occurs, and the deflected intensity is expected to be largely enhanced when the Bragg condition is satisfied. This transverse configuration is thus specially attractive to characterize periodically-poled crystals.

Eleven days after double lung transplantation for cystic fibrosis, an 18-year-old patient developed a disseminated Fusarium solani infection with tricuspid valve endocarditis. This infection occurred under fluconazole and immunosuppressive therapy with cyclosporin, prednisone and azathioprine, with a normal leucocyte count. Liposomal amphotericin B allowed blood culture negativation. The patient died from a bacterial septic shock.

We report Raman scattering spectroscopy in proton exchanged LiNbO 3 wave guides. Large differences have been observed according to the fabrication processes, and it is shown that. the soft proton exchange technique does not induce structural change in the crystal. Raman spectroscopy is pointed out to be an efficient technique to control the quality of the guides.

Our study is aimed to achieve electro-optic modulators with an enhanced stability even at long time. For this we focused our attention on the non-uniformities in the dielectric permittivity and electrical conductivity which appear in the various successive layers which constitute the optical device. We thus show that polaron luminescence and Raman spectroscopy can be efficiently used to control the uniformity of the electrical conductivity of the wafer prior to the fabrication, and then the Li-out-diffusion and Ti-in-diffusion during the process of the waveguide fabrication.

Photoluminescence attributed to small polarons Nb Li 4+ is recorded as function of temperature from 80 K to 290 K in nominally-pure congruent LiNbO 3 . It is found that the integrated area of the main peaks remains nearly constant at low temperature and then decreases sharply with activation energy of about 0.12 eV above 200 K. The limit between the two regimes is thought to correspond to the crossing point between the radiative and non-radiative lifetimes of the polaron excited state.

International audience; We propose in this paper a fast, sensitive and reliable technique of characterisation based on micro-spectroscopy (Raman and polaron luminescence), which allows at the determination of the chemical reduction profile after titanium diffusion or other high-temperature annealing treatments, and thus to the electrical conductivity, in the section of the waveguides. This profile allows us to predict the DC drift of active components using the electro-optical effect. Moreover, coupled with confocal microscopy, this technique can give 2D and 3D maps of a waveguide at micro scale.

The growth of iron-doped single-crystal fibers of lithium niobate was performed by the Laser Heated Pedestal Growth Technique for different Fe 2 O 3 contents in the feed rods. We used the polaron luminescence to explain the processes of iron substitution in iron-doped single-crystal fibers of lithium niobate. The interpretation of the polaron behavior as a function of iron concentration confirms several predicted effects as the decrease of the global amount of vacancies and the predominant role of the niobium in its polaronic or bipolaronic forms in the LN lattice.

Lithium niobate LiNbO/sub 3/ (LN) Mach-Zehnder interferometer (MZI) modulators are a key in high-speed optical communication systems. The optimization of integrated Mach-Zehnder interferometer modulator is discussed in this paper. We have extensively characterized the drift phenomena in a typical MZI modulator as a function of time, temperature and optical power. We have carried out optical and electrical measurements of the characteristics of the passive component and the active component as well. We also took into account of other physical properties such as pyroelectric effect, photovoltaic effect and photoconductivity. The electrical characteristics of the wafer and component were investigated and reported here. We present here the first results of the simulations which were obtained in this frame. These predictions are then compared with the effective electric field in the different layers and its time behavior.

International audience; The deflection of light in ferroelastic crystals results from refraction and reflection at domain walls. When the tilt angle of the principal axes in neighboring domains is small, simple relationships between the crystal birefringences and the angles of the deflected beams can be deduced from Snell's law of refraction. As a rule, this condition is satisfied at W-domain walls in ferroelastic species that have a biaxial prototype phase. In this case, measurement of the deflection angles permits one to determine the birefringences easily. This method has as its main advantages independence of the sample thickness and the need for only rough sample preparation. It is absolutely insensitive to temperature fluctuations. We have applied the method to crystals of rubidium hydrogen selenate and dihydrated barium chloride as illustrative examples.

International audience; The combination of phase, intensity, and contrast effects during electrooptic modulation is theoretically and exper- imentally investigated. One consequence of this combination is the modification of the amplitude of the single-frequency signals which are commonly used as working points for electrooptic mod- ulators and for the measurements of the electrooptic coefficients. Another consequence of direct intensity modulation is to shift the double-frequency points of the transfer function from the positions they normally occupy at the intensity extrema. They can even make them disappear if the direct intensity modulation is stronger than the phase modulation. Such phenomena are expected with any ferroelectric material in which a significant part of the incident light is deflected or scattered by domain walls or grain boundaries. They can lead to considerable mistakes in the determination of the electrooptic coefficients. Appropriate procedures to extract the different contributions are explained. Experimental results in rubidium hydrogen selenate are given, and consequences of the working of electrooptic modulators are discussed.

International audience; The refractive indices of rubidium hydrogen selenate are measured for several wavelengths at room tempera- ture, and the transmission spectrum is measured from the UV (240 nm) to the near IR (2000 nm). The ori- entation of the optical indicatrix with respect to the crystal axes is also determined at several wavelengths in the visible range. Using a new method based on the deflection of light by the ferroelastic domain structure, we also determine refined values for birefringence at several wavelengths. Finally, the dispersion of the three birefringences in the range 450 – 900 nm is deduced from polarimetric measurements. This set of results yields complete knowledge of the linear optical characteristics required for interpretation of the electro-optical and nonlinear optical properties of this compound.

International audience; We present optical and electrooptical characterization of ammonium hydrogen selenate (Nl4HSe04). The properties of this new electrooptic crystal are compared with these of rubidium hydrogen selenate (RbHSe04).

The frequency dispersion of the large electro-optic effect in rubidium hydrogen selenate is measured from 300 Hz to 200 kHz as a function of the direction of propagation. It is shown that the major coefficient is r42 (750 pm/V at 1 kHz). Both dielectric and electro-optic responses exhibit strong, perfectly correlated dispersions in this frequency range. The experimental results confirm the major contribution of domain dynamics in the huge electro-optic effect and are in perfect agreement with calculations based on the tilting of the optical indicatrix. The possible use of rubidium hydrogen selenate in low-frequency electro-optic modulators is briefly discussed.

Rubidium hydrogen selenate ( RbHSeO4) was recently reported as exhibiting one of the largest electro-optic coefficients ever measured in any material. We report on the dependence of the electro-optic properties on the dc electric field. This behavior can be interpreted by the change in the birefringence that is due to the domain reversal. This particular electro-optic effect also explains the large sensitivity of the electro-optical properties to the orientation of the laser beam-propagation direction with respect to the domain walls.

Evidence for maternal immune recognition of the fetus can be found during pregnancy, yet the conceptus remains unharmed. Indeed, in some cases immunizing the mother with cells sharing histocompatibility antigens with the fetus is beneficial to fetal survival. This could be due to the effect of maternally derived lymphokines on placental growth and function, according to the immunostimulation hypothesis. We demonstrate here that placental cells in culture proliferate upon the addition of T cell-derived lymphokines. The lymphokine activity has been separated from IL 2 and B cell growth factor, and copurified with IL 3 and granulocyte-macrophage colony-stimulating factor (CSF-GM). Recombinant CSF-GM and recombinant IL 3 showed a similar effect. The placental cells that proliferate in culture are of fetal origin and are characterized by strong adherence, phagocytosis, nonspecific esterase staining, and response to the macrophage-specific colony-stimulating factor CSF-1. In addition, treatment of pregnant females with anti-thymocyte serum as well as anti-Ly-2.1 monoclonal antibody, at gestational times before Ly-2 antigen appearance in the fetus, leads to a reduction of the proliferative and phagocytic capacity of day 12 placentae. These results clearly demonstrate that maternal T cells act upon fetally derived placental cells to improve their proliferative and phagocytic potential, and thus provide evidence for the immunostimulatory role of these cells during pregnancy.

The effects of human recombinant granulocyte and granulocyte-macrophage- (G- and GM-CSF), and of purified macrophage-stimulating factors (CSF-1), were tested on populations of leukemia cells isolated from 18 patients with different types of acute myeloid leukemia. Cell proliferation and differentiation were studied by culturing the cells in suspension for 7 days in the presence of CSF or medium alone. Spontaneous cell proliferation, as assessed by tritiated thymidine uptake, was observed in 9 of the 18 cases. GM-CSF induced proliferation in seven of the nine cases without spontaneous growth and increased spontaneous proliferation in nine cases. G-CSF added alone was also found to strongly stimulate leukemic blast cell proliferation, in which a translocation involving the long arm of chromosome 17 was observed. Low levels of CSF-1 stimulation were also observed in some cases. No clear morphological modification supporting evidence of terminal differentiation was observed, whereas modulation of some cell surface antigens was detected by flow cytometry. Thus, most leukemia cells still depend on growth factors for their proliferation, GM-CSF appearing the most effective. On the other hand these factors were not able to induce terminal differentiation.

The acrylamide gel electrophoresis of rabbit serum, of rabbit tubal secretions at the oestrus stage (STO) and at the luteal stage (STL), followed by immunodiffusion with anti-serum, was done to detect any tubal proteins which were not found in the rabbit serum. The anti-rabbit STO goat anti-serum was absorbed with rabbit plasma in order to purify antibodies to proteins found specifically in tubal secretions. This technique revealed the presence of a protein (STx) in STO and STL but not in the rabbit serum. The electrophoretic migration (Rf = 0.72) of the tubal protein (STx) is similar to uteroglobin (Rf = 0.74). The tubal protein was detected immunologically only in tissues where uteroglobin had been found by other workers: lungs, semen, Fallopian tubes and uterine secretions (5 days post-ovulation); further more a complete identity for the precipitating line existed between these extracts. These results corroborate the presence of uteroglobin or of a very similar protein in oestrus of luteal tubal secretions and in some other rabbit tissues.