Evolution of the potential-energy surface of amorphous silicon

The link between the energy surface of bulk systems and their dynamical properties is generally difficult to establish. Using the activation-relaxation technique (ART nouveau), we follow the change in the barrier distribution of a model of amorphous silicon as a function of the degree of relaxation. We find that while the barrier-height distribution, calculated from the initial minimum, is a unique function that depends only on the level of distribution, the reverse-barrier height distribution, calculated from the final state, is independent of the relaxation, following a different function. Moreover, the resulting gained or released energy distribution is a simple convolution of these two distributions indicating that the activation and relaxation parts of a the elementary relaxation mechanism are completely independent. This characterized energy landscape can be used to explain nano-calorimetry measurements.Comment: 5 pages, 4 figure

Relationship between biomarkers of muscle damage and redox status in response to a weightlifting training session: effect of time-of-day

The aims of the present study were to: (1) investigate the effect of a weightlifting training session and time-of-day (TOD) upon biological parameters (i.e., oral temperature, hematological, C-reactive protein (CRP), and oxidative stress) and (2) assess their possible link with muscle damage responses. Nine weightlifters (21 ± 0.5 years) performed, in a randomized order, three Olympic-Weightlifting sessions (i.e., at 08:00, 14:00, and 18:00). Blood samples were collected at rest, 3 min and 48 h after each training session. Between pre- and post-training session, ANOVA showed significant increases in oxidative stress markers at the three TODs (p < 0.01) and significant increases for creatine kinase (CK) and lactate dehydrogenase (LDH) only at 08:00 and 18:00 (p < 0.05). At rest, the results showed a significant diurnal variation for the majority of the selected parameters except for malondialdehyde (MDA), total bilirubin, and CRP with higher values observed at 18:00 (p < 0.05). After the training session, given the higher rate of increase during the morning session, these diurnal variations persisted for temperature and WBC (p < 0.01) and were suppressed for CK, LDH, uric acid (UA), catalase, and glutathione peroxidase. The main significant correlations (p < 0.001) were observed between: (1) CK and MDA (r = 0.6) and CK and UA (r = 0.66 and r = 0.82) during the morning and evening training sessions; (2) CK and CRP only during the morning session (r = 0.5); and (3) CRP and WBC during the three training sessions (r = 0.8). In conclusion, the present findings: (1) confirm that the muscle damage responses could be induced by a high level of oxidative stress and (2) suggest to avoid scheduling training sessions in the morning given the higher muscle damage, inflammatory, and oxidative responses at this TOD

An improved geometric inequality via vanishing moments, with applications to singular Liouville equations

We consider a class of singular Liouville equations on compact surfaces motivated by the study of Electroweak and Self-Dual Chern-Simons theories, the Gaussian curvature prescription with conical singularities and Onsager's description of turbulence. We analyse the problem of existence variationally, and show how the angular distribution of the conformal volume near the singularities may lead to improvements in the Moser-Trudinger inequality, and in turn to lower bounds on the Euler-Lagrange functional. We then discuss existence and non-existence results.Comment: some references adde

Constitutively elevated levels of SOCS1 suppress innate responses in DF-1 immortalised chicken fibroblast cells.

The spontaneously immortalised DF-1 cell line is rapidly replacing its progenitor primary chicken embryo fibroblasts (CEFs) for studies on avian viruses such as avian influenza but no comprehensive study has as yet been reported comparing their innate immunity phenotypes. We conducted microarray analyses of DF-1 and CEFs, under both normal and stimulated conditions using chicken interferon-α (chIFN-α) and the attenuated infectious bursal disease virus vaccine strain PBG98. We found that DF-1 have an attenuated innate response compared to CEFs. Basal expression levels of Suppressor of Cytokine Signalling 1 (chSOCS1), a negative regulator of cytokine signalling in mammals, are 16-fold higher in DF-1 than in CEFs. The chSOCS1 “SOCS box” domain (which in mammals, interacts with an E3 ubiquitin ligase complex) is not essential for the inhibition of cytokine-induced JAK/STAT signalling activation in DF-1. Overexpression of SOCS1 in chIFN-α-stimulated DF-1 led to a relative decrease in expression of interferon-stimulated genes (ISGs; MX1 and IFIT5) and increased viral yield in response to PBG98 infection. Conversely, knockdown of SOCS1 enhanced induction of ISGs and reduced viral yield in chIFN-α-stimulated DF-1. Consequently, SOCS1 reduces induction of the IFN signalling pathway in chicken cells and can potentiate virus replication

Efecto de la germinación sobre la composición química y la actividad antioxidante de aceites de linaza (Linum usitatissimum L).

The present study was carried out to determine the changes in proximate composition and physicochemical characteristics of flaxseed during germination. Flaxseed was germinated for 4 days and observations were taken every day throughout the study. Changes in the seed reserve and antioxidant activity were determined during germination. The oil content of the cultivar decreased from 35.10 to 27.22%. During the germination period, the total protein content increased to 23.84%. Germinated flaxseed showed significantly higher unsaturated as compared to saturated fatty acid ratios and higher calculated oxidizability (Cox) values. The Saponification value ranged from 182 to 192 mg KOH·g–1 oil during germination. The highest peroxide value (2.4 mequiv O2·kg−1 oil) was observed at the end of germination. The unsaponifiable contents ranged from 1.62 to 1.18%. The oxidation value of the oil samples were statistically in the same range (4.1–6.4%). After 4 days of germination, oil stability was reduced to 1.0 h. The increase in ascorbic acid content was steady. Total phenolic acid contents differed significantly. The greatest concentration was detected in non germinated flaxseed oil. Germinated Flaxssed oil showed an important free radical scavenging activity towards 1-1-diphenyl-2-picrylhydrazyl (DPPH) free radicals.El presente estudio se llevó a cabo para determinar los cambios en la composición y características físico-químicas de aceites de linaza durante la germinación. La linaza se germinó durante 4 días y el estudio se realizó todos los días durante este proceso. Se determinaron los cambios en la reserva de las semilla y la actividad antioxidante. El contenido de aceite de los cultivos disminuyó de 35,10 a 27,22%. Durante este periodo, el contenido de proteína total aumentó a 23,84%. La linaza germinada mostró valores significativamente más altos de la relación de ácidos grasos insaturados frente a saturados y mayor facilidad de oxidación (Cox). El índice de saponificación varió desde 182 hasta 192 mg KOH·g−1 de aceite durante la germinación. El índice de peróxido más alto (2,4 mequiv O2·kg−1 de aceite) se observó al final de la germinación. El contenido de materia insaponificable varió desde 1,62 hasta 1,18%. La oxidación de las muestras de aceite fueron estadísticamente del mismo rango (4.1 a 6.4%). Después de 4 días de germinación, la estabilidad del aceite se redujo a 1,0 h. El aumento en contenido de ácido ascórbico fue estable. Los contenidos totales de ácidos fenólicos diferían significativamente. La mayor concentración se detectó en el aceite de linaza no germinado. El aceite de linaza germinado mostró una importante actividad de eliminación de radicales libres hacia 1-1-difenil-2-picrilhidrazil (DPPH)

Complications orbitaires de la polypose nasosinusienne de l’enfant

La polypose nasosinusienne (PNS) est une pathologie rare chez l’enfant. La symptomatologie clinique est habituellement celle de l’adulte. Exceptionnellement, une complication locorégionale lui est révélatrice. A travers deux observations de PNS diagnostiquées suite à une complication orbitaire, on discute les particularités cliniques de cette entité ainsi que ses implications thérapeutiques. Il s’agissait de deux enfants âgés de 13 ans ayant été hospitalisés pour une exophtalmie unilatérale d’apparition aiguë. L’examen clinique a découvert une PNS surinfectée évoquant alors le diagnostic de complication orbitaire d’origine infectieuse, confirmé par l’imagerie. Le traitement a associé un drainage chirurgical d’urgence de l’abcès orbitaire par voie externe paracanthale interne, suivi par une corticothérapie locale. L’ethmoïdectomie a été nécessaire dans un cas. L’évolution était favorable dans les deux cas avec une stabilisation de la PNS et une absence de signes de récidive de l’infection orbitaire

Localisation nasosinusienne des tumeurs plasmocytaires

Introduction : Les tumeurs plasmocytaires représentent 3 à 4% des tumeurs des cavités naso-sinusiennes. Elles nécessitent un bilan diagnostique spécifique et une prise en charge adéquate. Nous nous proposons d’étudier les particularités diagnostiques et thérapeutiques des plasmocytomes naso-sinusiens. Matériel et méthodes : Notre étude est rétrospective comportant 5 cas de plasmocytomes naso-sinusiens confirmés histologiquement.Résultats : Il s’agit de 3 hommes et 2 femmes âgés de 32 à 77 ans. Le plasmocytome avait une localisation sphénoïdale dans un cas, nasale dans 2 cas, ethmoïdo-nasale dans un cas et naso-maxillaire dans le cas restant. Il s’agissait d’un myélome multiple dans un cas. Trois patients ont eu une radiothérapie. Celle-ci était associée à une chimiothérapie dans le cas du myélome multiple et à une exérèse chirurgicale dans les 2 autres cas La chirurgie a été seule dans un cas. La chimiothérapie exclusive a été proposée dans un cas de plasmocytome localement avancé mais le patient a été perdu de vue. Pour les patients suivis, une seule récidive a été notée à 18 mois.Conclusion : La présentation clinique des plasmocytomes nasosinusiens est aspécifique. Le diagnostic est confirmé par l’histologie. Le pronostic est dominé par la présence ou non d’un myélome multiple et par la taille tumorale. Un suivi prolongé est nécessaire.Mots clés : plasmocytome extramédullaire ; cavités naso-sinusiennes ; radiothérapie ; chirurgie.Introduction: Plasmocytomas represent 3-4% of tumors naso-sinus cavities. Their diagnosis requires a specific investigations and adequate management. We report 5 cases of naso-sinus plasmacytoma and we propose to study their diagnostic and therapeutic characteristics.Materials and methods: Our study is retrospective including 5 cases of naso-sinus plasmacytoma confirmed histologically.Results: There were 3 men and 2 women aged 32 to 77 years. The plasmacytoma had a sphenoidal location in one case, nasal in 2 cases, ethmoid-nasal in one case and naso-maxillary in the remaining case. Multiple myeloma was found in one case. Three patients underwent radiotherapy. This was associated with chemotherapy in multiple myeloma case and surgical resection in 2 cases. Surgery alone was performed in one case. Exclusive chemotherapy was proposed in a case of plasmacytoma locally advanced but the patient was lost sight of. For followed patients, only one recurrence was noted at 18 months.Conclusion: The clinical presentation of sinonasal plasmacytomas is aspecific. The diagnosis is confirmed by histology. The prognosis is dominated by the presence or absence of multiple myeloma and tumor size. Prolonged follow-up is necessary.Keywords : extramedullary plasmacytoma, naso-sinus cavities, radiotherapy ; surgery

Abces amibien cerebral: a propos de trois cas avec revue de la litterature

Introduction L’abcès amibien cérébral est une infection rare mais mortelle. Depuis son identification en 1965, peu de cas ont été observés dans le monde entier.Matériel et méthode Les objectifs de cette étude étaient de caractériser les aspects cliniques, radiologiques, histologique, pronostic ainsi que thérapeutique de cette pathologie avec une revue de la littérature. Nous rapportons trois cas d’abcès amibien cérébral qui ont été admis dans notre service entre 2010 et 2013.Résultats Il s’agit de deux hommes et une femme, âgés respectivement de 33, 43 et 56 ans qui ont été opérés. Le diagnostic a été confirmé par les examens histologique et sérologique. Nous n’avons observé aucune mortalité.Conclusion Il s’agit d’une atteinte sporadique mais représente un problème de santé publique et dont le pronostic est habituellement sombre.Mots clés : amibiase; abcès cérébral; IRM ; TDM; examen histologiqu