Influence of oxygen deficiency on optical and dielectric properties of La0.75Ba0.10Sr0.15FeO2.875-δ compounds

Using the conventional sol-gel process, the series of non-stoichiometric oxygen lanthanum ferrites with the formula 0.750.100.152.875 ― (δ=0.00, 0.125 and 0.25) were prepared. X-ray diffraction analysis confirmed the formation of the orthorhombic structure with Pnma space group. In the present work, we confirm the potential of 0.750.100.15 2.875 ― (δ=0.00, 0.125 and 0.25) as an efficient dielectric material. All samples show high absorbance in the visible region with wavelength above 300 nm. The optical band gaps are found to increase from 3.25 to 4.1 with increasing oxygen vacancy concentration. The dielectric constant, dielectric loss and loss factor were carried out as a function of oxygen vacancy concentration and frequency (102 -106 Hz) at room temperature. The variation of dielectric constant with frequency indicates dispersive behavior and giant dielectric response (more than 104 ) at low frequencies for compounds deficient in oxygen. Such value of makes ′ these samples an interesting material to be used in applications namely the reduction of electronic components size. To summarize, incorporating vacancy oxygen enhances the dielectric properties. Thus, the interesting dielectric constant and weak loss strengthen the use for potential applications.publishe

COMPETING MECHANISMS OF MOLECULAR HYDROGEN FORMATION IN CONDITIONS RELEVANT TO THE INTERSTELLAR MEDIUM

International audienceThe most efficient mechanism of the formation of molecular hydrogen in the current universe is by association of hydrogen atoms on the surface of interstellar dust grains. The details of the processes of its formation and release from the grain are of great importance in the physical and chemical evolution of the space environmentswhere it takes place. Themain puzzle is still the fate of the 4.5 eV released in H2 formation and whether it goes into internal energy (rovibrational excitation), translational kinetic energy, or heating of the grain. The modality of the release of this energy affects the dynamics of the ISM and its evolution toward star formation.We present results of the detection of the rovibrational states of the just-formed H2 as it leaves the surface of a silicate.We find that rovibrationally excited molecules are ejected into the gas phase immediately after formation over a much wider range of grain temperatures than anticipated. Our results can be explained by the presence of twomechanisms ofmolecule formation that operate in partially overlapping ranges of grain temperature. A preliminary analysis of the relative importance of these two mechanisms is given. These unexpected findings, which will be complemented with experiments on the influence of factors such as silicate morphology, should be of great interest to the astrophysics and astrochemistry communities

Metastase de la voûte crânienne Revelant un carcinome differencie De la thyroïde

Les métastases des carcinomes thyroïdiens au niveau de la voûte crânienne sont extrêmement rares. Bien que ces métastases soient de mauvais pronostic, la détection précoce et l’administration d’un traitement approprié peuvent améliorer la survie et la qualité de vie. Nous rapportons deux cas de carcinomes différenciés thyroïdiens révélés par une métastase de la voûte crânienne.Mots clés: métastase, voûte crânienne, cancer de la thyroïdeThyroid carcinoma with metastasis to the cranial vault is extremely rare. Although these metastasis had poor prognosis, early detection and administration of appropriate therapy using radioactive iodine seems likely to improve the survival rate and quality of life. We report two cases of differentiated thyroid carcinoma revealed by vault metastasis.Keywords: metastasis, cranial vault, thyroid carcinom

Volatile Constituents And Antimicrobial Activity Of Lavandula Stoechas L. Oil From Tunisia

International audienceAn oil obtained from the dried leaves of Lavandula stoechas L. in 0.77% yield was analyzed by capillary GC and GUMS. Fenchone (68.2%) and camphor (11.2%) were the main components of the 28 identified molecules. This oil has been tested for antimicrobial activity against six bacteria, and two fungi. The results showed that this oil was active against all of the tested strains; Staphylococcus aureus was the more sensitive strain

ERS International Congress 2022: highlights from the Respiratory Clinical Care and Physiology Assembly

It is a challenge to keep abreast of all the clinical and scientific advances in the field of respiratory medicine. This article contains an overview of the laboratory-based science, clinical trials and qualitative research that were presented during the 2022 European Respiratory Society International Congress within the sessions from the five groups of Assembly 1 (Respiratory Clinical Care and Physiology). Selected presentations are summarised from a wide range of topics: clinical problems, rehabilitation and chronic care, general practice and primary care, mobile/electronic health (m-health/e-health), clinical respiratory physiology, exercise and functional imaging

Determining the genome-wide kinship coefficient seems unhelpful in distinguishing consanguineous couples with a high versus low risk for adverse reproductive outcome

Background: Offspring of consanguineous couples are at increased risk of congenital disorders. The risk increases as parents are more closely related. Individuals that have the same degree of relatedness according to their pedigree, show variable genomic kinship coefficients. To investigate whether we can differentiate between couples with high- and low risk for offspring with congenital disorders, we have compared the genomic kinship coefficient of consanguineous parents with a child affected with an autosomal recessive disorder with that of consanguineous parents with only healthy children, corrected for the degree of pedigree relatedness. Methods: 151 consanguineous couples (73 cases and 78 controls) from 10 different ethnic backgrounds were genotyped on the Affymetrix platform and passed quality control checks. After pruning SNPs in linkage disequilibrium, 57,358 SNPs remained. Kinship coefficients were calculated using three different toolsets: PLINK, King and IBDelphi, yielding five different estimates (IBDelphi, PLINK (all), PLINK (by population), King robust (all) and King homo (by population)). We performed a one-sided Mann Whitney test to investigate whether the median relative difference regarding observed and expected kinship coefficients is bigger for cases than for controls. Furthermore, we fitted a mixed effects linear model to correct for a possible population effect. Results: Although the estimated degrees of genomic relatedness with the different toolsets show substantial variability, correlation measures between the different estimators demonstrated moderate to strong correlations. Controls have higher point estimates for genomic kinship coefficients. The one-sided Mann Whitney test did not show any evidence for a higher median relative difference for cases compared to controls. Neither did the regression analysis exhibit a positive association between case–control status and genomic kinship coefficient. Conclusions: In this case–control setting, in which we compared consanguineous couples corrected for degree of pedigree relatedness, a higher degree of genomic relatedness was not significantly associated with a higher likelihood of having an affected child. Further translational research should focus on which parts of the genome and which pathogenic mutations couples are sharing. Looking at relatedness coefficients by determining genome-wide SNPs does not seem to be an effective measure for prospective risk assessment in consanguineous parents

Treatment and prognosis of leptomeningeal disease secondary to metastatic breast cancer: A single-centre experience.

Purpose Leptomeningeal disease (LMD) is an uncommon complication of advanced breast cancer. The prognosis is poor, and although radiotherapy (RT), systemic and intra-thecal (IT) chemotherapy are accepted treatment modalities, efficacy data are limited. This study was designed to evaluate potential predictors of survival in this patient group.Methods Breast cancer patients with LMD diagnosed by MRI in a 10-year period (2004-2014) were identified from electronic patient records. PFS and OS estimates were calculated using Kaplan-Meier method, with planned sub-group analysis by treatment modality. Cox regression was employed to identify significant prognostic variables.Results We identified 182 eligible patients; all female, median age at LMD diagnosis 52.5 years (range 23-80). Ninety patients (49.5%) were ER positive/HER2 negative; 48 (26.4%) were HER2 positive, and 27 (14.8%) were triple negative. HER2 status was unknown in 17 (9.3%). Initial management of LMD was most commonly whole or partial brain RT in 62 (34.1%), systemic therapy in 45 (24.7%) or supportive care alone in 37 (20.3%). Fourteen patients (7.7%) underwent IT chemotherapy, of whom two also received IT trastuzumab. From diagnosis of LMD, the median PFS was 3.9 months (95%CI 3.2-5.0) and median OS was 5.4 months (95%CI 4.2-6.6). Patients treated with systemic therapy had the longest OS (median 8.8 months, 95%CI 5.5-11.1), compared to RT; 6.1 months (95%CI 4.2-7.9 months), IT therapy; 2.9 months (95%CI 1.2-5.8) and supportive care; 1.7 months (95%CI 0.9-3.0). On multivariable analysis, triple negative histology, concomitant brain metastases, and LMD involving both the brain and spinal cord were associated with poor OS.Conclusions Breast cancer patients with triple negative LMD, concomitant brain metastases or LMD affecting both the spine and brain have the poorest prognosis. Clinical trials to identify more effective treatments for these patients are urgently needed

Absence of mutations in four genes encoding for congenital cataract and expressed in the human brain in Tunisian families with cataract and mental retardation

<p>Abstract</p> <p>Background</p> <p>To identify the genetic defect associated with autosomal recessive congenital cataract (ARCC), mental retardation (MR) and ARCC, MR and microcephaly present in most patients in four Tunisian consanguineous families.</p> <p>Methods</p> <p>We screened four genes implicated in congenital cataract by direct sequencing in two groups of patients; those affected by ARCC associated to MR and those who presented also microcephaly. Among its three genes <it>PAX6</it>, <it>PITX3 </it>and <it>HSF4 </it>are expressed in human brain and one gene <it>LIM2 </it>encodes for the protein MP20 that interact with the protein galectin-3 expressed in human brain and plays a crucial role in its development. All genes were screened by direct sequencing in two groups of patients; those affected by ARCC associated to MR and those who presented also microcephaly.</p> <p>Results</p> <p>We report no mutation in the four genes of congenital cataract and its flanking regions. Only variations that did not segregate with the studied phenotypes (ARCC associated to MR, ARCC associated with MR and microcephaly) are reported. We detected three intronic variations in <it>PAX6 </it>gene: IVS4 -274insG (intron 4), IVS12 -174G>A (intron12) in the four studied families and IVS4 -195G>A (intron 4) in two families. Two substitutions polymorphisms in <it>PITX3 </it>gene: c.439 C>T (exon 3) and c.930 C>A (exon4) in one family. One intronic variation in <it>HSF4 </it>gene: IVS7 +93C>T (intron 7) identified in one family. And three intronic substitutions in <it>LIM2 </it>gene identified in all four studied families: IVS2 -24A>G (intron 2), IVS4 +32C>T (intron 4) and c.*15A>C (3'-downstream sequence).</p> <p>Conclusion</p> <p>Although the role of the four studied genes: <it>PAX6</it>, <it>PITX3</it>, <it>HSF4 </it>and <it>LIM2 </it>in both ocular and central nervous system development, we report the absence of mutations in all studied genes in four families with phenotypes associating cataract, MR and microcephaly.</p

Grain Surface Models and Data for Astrochemistry

AbstractThe cross-disciplinary field of astrochemistry exists to understand the formation, destruction, and survival of molecules in astrophysical environments. Molecules in space are synthesized via a large variety of gas-phase reactions, and reactions on dust-grain surfaces, where the surface acts as a catalyst. A broad consensus has been reached in the astrochemistry community on how to suitably treat gas-phase processes in models, and also on how to present the necessary reaction data in databases; however, no such consensus has yet been reached for grain-surface processes. A team of ∼25 experts covering observational, laboratory and theoretical (astro)chemistry met in summer of 2014 at the Lorentz Center in Leiden with the aim to provide solutions for this problem and to review the current state-of-the-art of grain surface models, both in terms of technical implementation into models as well as the most up-to-date information available from experiments and chemical computations. This review builds on the results of this workshop and gives an outlook for future directions