1,014 research outputs found

    Etude pour une conservation Ă  long terme des documents de la BibliothĂšque des Conservatoire et Jardin botaniques de la Ville de GenĂšve

    Get PDF
    Ce travail a pour objectif d’effectuer une rĂ©flexion sur la bonne maniĂšre de gĂ©rer et de conserver les documents d’archives, pour ainsi mettre en place une procĂ©dure qui montre les Ă©tapes de conditionnement adĂ©quat pour chaque type de support que l’on peut rencontrer dans une bibliothĂšque ou centre d’archives. Il a Ă©tĂ© rĂ©alisĂ© pour la BibliothĂšque des Conservatoire et Jardin botaniques (BCJB) de la Ville de GenĂšve, mais peut s’appliquer aux autres institutions qui ont besoin de conserver leurs documents. DivisĂ© en deux axes, ce travail montre une synthĂšse des diffĂ©rentes pratiques de la conservation dans les institutions genevoises et europĂ©ennes, pour pouvoir intĂ©grer ces pratiques Ă  la BCJB. Par la suite, un bilan de conservation ainsi que le traitement du fonds du botaniste genevois Boissier (1810-1885) montrent mes choix au niveau du traitement de ces documents. Ce traitement m’a permis d’observer l’état actuel de ces fonds et de pouvoir aider le personnel de la BCJB par la suite Ă  mettre en place les Ă©tapes pour construire une politique de conservation. A l’heure oĂč l’information doit ĂȘtre accessible partout et Ă  tout moment, les institutions culturelles travaillent Ă  l’accomplissement de cet objectif. Avant de pouvoir mener Ă  bien ce projet d’accessibilitĂ©, par exemple en numĂ©risant les documents d’archives, il faut tout d’abord se poser une question essentielle «Qu’est-ce que qui est numĂ©risable si on ne conserve pas les objets ou les documents rares et prĂ©cieux dans leur Ă©tat d’origine? ». La conservation des objets est primordiale afin de pouvoir lĂ©guer cet hĂ©ritage patrimonial aux successeurs de la BibliothĂšque des Conservatoire et Jardin Botaniques Ă  l’avenir

    Robustness of dynamically gradient multivalued dynamical systems

    Get PDF
    In this paper we study the robustness of dynamically gradient multivalued semiflows. As an application, we describe the dynamical properties of a family of Chafee-Infante problems approximating a differential inclusion studied in J. M. Arrieta, A. Rodríguez-Bernal and J. Valero, Dynamics of a reaction-diffusion equation with a discontinuous nonlinearity, International Journal of Bifurcation and Chaos, 16 (2006), 2965-2984, proving that the weak solutions of these problems generate a dynamically gradient multivalued semiflow with respect to suitable Morse sets.Ministerio de Educación, Cultura y DeporteMinisterio de Economía y CompetitividadJunta de AndalucíaFundação de Amparo à Pesquisa do Estado de São PauloConselho Nacional de Desenvolvimento Científico e Tecnológic

    Li-decorated Pmmn8 phase of borophene for hydrogen storage. A van der Waals corrected density-functional theory study

    Get PDF
    ProducciĂłn CientĂ­ficaWe performed standard and van der Waals-corrected density functional theory calculations to investigate the hydrogen storage capacity of a phase of borophene with Pmmn symmetry and nonzero thickness. This borophene sheet (Pmmn8) has 8 atoms in its unit cell and is more stable than the planar sheet and that the corrugated Pmmn2 sheet (2 atoms in the unit cell). Our results show that, in pristine form, the Pmmn8 sheet is not suited for hydrogen storage applications. However, decoration with Li atoms and strain increase the hydrogen storage ability of the sheet. We performed also a detailed quantum chemical topological analysis that shows that the B-Li interaction in the hydrogenated Li-decorated Pmmn8 sheet is ionic. Our results for the adsorption of H2 on the Li-decorated Pmmn8 sheet are compared with those obtained for the adsorption of H2 on Ti-decorated zigzag graphene nanoribbons.Ministerio de Ciencia, InnovaciĂłn y Universidades (Project FIS2014-59279-P)Junta de Castilla y LeĂłn (Project VA124G18)Xunta de Galicia (AGRUP2015/11, ED 431E2018-08 and GRC ED431C

    Chondrogenic Potential of Subpopulations of Cells Expressing Mesenchymal Stem Cell Markers Derived from Human Synovial Membranes

    Get PDF
    [Abstract] In this study we analyzed the chondrogenic potential of subpopulations of mesenchymal stem cells (MSCs) derived from human synovial membranes enriched for CD73, CD106, and CD271 markers. Subpopulations of human synovial membrane MSCs enriched for CD73, CD106, and CD271 markers were isolated using a cytometry sorter and characterized by flow cytometry for MSC markers. The expression of Sox9, Nanog, and Runx2 genes by these cells was measured by reverse transcriptase-polymerase chain reaction. The chondrogenesis of each subpopulation was assessed by culturing the cells in a defined medium to produce spontaneous spheroid formation and differentiation towards chondrocyte-like cells. The examination of the spheroids by histological and immunohistochemical analyses for collagen type II (COL2), aggrecan, collagen type I (COL1), metalloprotease 13 (MMP13), and collagen type X (COLX) levels were performed to assess their chondrogenesis capacity. The adipogenesis and osteogenesis potential of each subpopulation was determined using commercial media; the resulting cells were stained with oil red O or red alizarin to test the degree of differentiation. The subpopulations had different profiles of cells positive for the MSC markers CD44, CD69, CD73, CD90, and CD105 and showed different expression levels of the genes Sox9, Nanog, and Runx2 involved in chondrogenesis, undifferentiation, and osteoblastogenesis, respectively. Immunohistochemical analysis demonstrated that COL1, COL2, COLX, MMP13, and aggrecan were expressed in the spheroids as soon as 14 days of culture. The CD271+ subpopulation expressed the highest levels of COL2 staining compared to the other subpopulations. CD105 and Runx2 were shown by immunohistochemistry and genetic analysis to have significantly higher expression CD271+ subpopulation than the other subpopulations. Spheroids formed from CD271-enriched and CD73-enriched MSCs from normal human synovial membranes mimic the native cartilage extracellular matrix more closely than CD106+ MSCs and are possible candidates for use in cartilage tissue engineering. Both cell types have potential for promoting the differentiation of MSCs into chondrocytes, presenting new possibilities for achieving intrinsic cartilage repair.Servizo Galego de SaĂșde; PS07/86Instituto de Salud Carlos III; CIBER BBN CB06-01-0040Instituto de Salud Carlos III; PI-08/202

    Differentiation of Synovial CD-105+ Human Mesenchymal Stem Cells into Chondrocyte-like Cells through Spheroid Formation

    Get PDF
    [Abstract] Mesenchymal stem cells (MSCs) have the capacity to differentiate into several cell lineages, some of which can generate bone, cartilage, or adipose tissue. The presence of MSCs in the synovial membrane was recently reported. Data from comparative studies of MSCs derived from various mesenchymal tissues suggest that MSCs from synovial membranes have a superior chondrogenesis capacity. Previous chondrogenic differentiation studies have used the total population of MSCs, including cells with several MSC markers, such as CD44, CD90, CD105, or CD73. However the chondrogenic capacity of an individual population of MSCs has not been examined. Our aim was to study the chondrogenic capacity of the cellular MSC subset, CD105+, derived from synovial membrane tissues of patients with osteoarthritis (OA) and normal donors. The tissues were digested with a cocktail of collagenase/dispase and the isolated MSCs were seeded into plates. The subpopulation of CD105+-MSCs was separated using a magnetic separator. The MSCs were then differentiated towards chondrocyte-like cells using a specific medium to promote spheroid formation. Spheroids were collected after 14, 28, and 46 days in chondrogenic medium and stained with hematoxylin, eosin, Safranin O or Alcian blue to evaluate the extracellular matrix. Immunohistochemistry was performed to study collagen types I (COLI) and II (COLII) and aggrecan expression. Phenotypic characterization of the isolated CD105+-MSCs shows that these cells are also positive for CD90 and CD44, but negatives for CD34 and CD45. In addition, this cellular subset expressed Sox-9. Spheroids appeared after 7 days in culture in the presence of chondrogenic medium. Our studies show no differences between MSCs obtained from OA and normal synovial membranes during chondrogenesis. The morphological analysis of spheroids revealed characteristics typical of chondrocyte cells. The intensity of Safranin O, Alcian blue and aggrecan staining was positive and constant throughout the culture period. However, the intensity of COL2 staining was higher at 28 days (84.29 ± 0.1 U) than at 46 days (61.28 ± 01 U), while COL1 staining was not detected in any samples analyzed. These results were confirmed by reverse transcriptase-polymerase chain reaction assays. We conclude that the cellular subset of CD105+-MSCs has chondrogenic capacity. The study also show the similar chondrogenic capacity of CD105+-MSCs cultured from normal and OA synovial membranes. J. Cell. Biochem. 108: 145–155, 2009.Servizo Galego de SaĂșde; PS07/8

    Umbilical Cord as a Mesenchymal Stem Cell Source for Treating Joint Pathologies

    Get PDF
    [Abstract] Articular cartilage disorders and injuries often result in life-long chronic pain and compromised quality of life. Regrettably, the regeneration of articular cartilage is a continuing challenge for biomedical research. One of the most promising therapeutic approaches is cell-based tissue engineering, which provides a healthy population of cells to the injured site but requires differentiated chondrocytes from an uninjured site. The use of healthy chondrocytes has been found to have limitations. A promising alternative cell population is mesenchymal stem cells (MSCs), known to possess excellent proliferation potential and proven capability for differentiation into chondrocytes. The “immunosuppressive” property of human MSCs makes them an important candidate for allogeneic cell therapy. The use of allogeneic MSCs to repair large defects may prove to be an alternative to current autologous and allogeneic tissue-grafting procedures. An allogeneic cell-based approach would enable MSCs to be isolated from any donor, expanded and cryopreserved in allogeneic MSC banks, providing a readily available source of progenitors for cell replacement therapy. These possibilities have spawned the current exponential growth in stem cell research in pharmaceutical and biotechnology communities. Our objective in this review is to summarize the knowledge about MSCs from umbilical cord stroma and focus mainly on their applications for joint pathologies.Ministerio de Economía y Competitividad; PLE2009-0144Instituto de Salud Carlos III; CB06-01-004

    Bronchoscopy for foreign body removal: where is the delay?

    Get PDF
    This was a retrospective analysis of the medical charts of 145 patients treated at the Bronchoscopy and Thoracic Surgery Clinic of the Hospital das ClĂ­nicas da Universidade Estadual de Campinas (HC-Unicamp, State University of Campinas Hospital das ClĂ­nicas) over a period of 10 years. There was a significant difference related to the site of first medical visit (Unicamp-HC versus other institutions) in terms of the time elapsed between the suspicion of bronchial aspiration and the actual respiratory endoscopic examination. However, no significant difference was found in the rate of positive results. The low number of referral centers that provide emergency respiratory endoscopy can negatively influence the treatment of patients under suspicion of bronchial aspiration, jeopardizing the overall recovery in the mid- and long-term.Analisaram-se retrospectivamente os prontuĂĄrios de 145 doentes admitidos no Serviço de Broncoscopia e Cirurgia TorĂĄcica do Hospital das ClĂ­nicas da Universidade Estadual de Campinas (HC-Unicamp) num perĂ­odo de 10 anos. Houve diferença estatĂ­stica relacionada com o local de consulta inicial (HC-Unicamp versus outros serviços) em termos do tempo gasto desde a suspeita de broncoaspiração atĂ© a realização do exame endoscĂłpico respiratĂłrio. No entanto, nĂŁo houve diferença significativa entre o Ă­ndice de positividade do exame. O baixo nĂșmero de centros de referĂȘncia para endoscopia respiratĂłria de urgĂȘncia pode influenciar negativamente no atendimento a doentes com suspeita de broncoaspiração, piorando a evolução em mĂ©dio e longo prazo3411956958This was a retrospective analysis of the medical charts of 145 patients treated at the Bronchoscopy and Thoracic Surgery Clinic of the Hospital das ClĂ­nicas da Universidade Estadual de Campinas (HC-Unicamp, State University of Campinas Hospital das ClĂ­nicas) over a period of 10 years. There was a significant difference related to the site of first medical visit (Unicamp-HC versus other institutions) in terms of the time elapsed between the suspicion of bronchial aspiration and the actual respiratory endoscopic examination. However, no significant difference was found in the rate of positive results. The low number of referral centers that provide emergency respiratory endoscopy can negatively influence the treatment of patients under suspicion of bronchial aspiration, jeopardizing the overall recovery in the mid- and long-ter

    Analysis of the Chondrogenic Potential and Secretome of Mesenchymal Stem Cells Derived from Human Umbilical Cord Stroma

    Get PDF
    [Abstract] Mesenchymal stem cells (MSCs) from umbilical cord stroma were isolated by plastic adherence and characterized by flow cytometry, looking for cells positive for OCT3/4 and SSEA-4 as well as the classic MSC markers CD44, CD73, CD90, Ki67, CD105, and CD106 and negative for CD34 and CD45. Quantitative reverse transcriptase–polymerase chain reaction analysis of the genes ALP, MEF2C, MyoD, LPL, FAB4, and AMP, characteristic for the differentiated lineages, were used to evaluate early and late differentiation of 3 germ lines. Direct chondrogenic differentiation was achieved through spheroid formation by MSCs in a chondrogenic medium and the presence of chondrogenic markers at 4, 7, 14, 28, and 46 days of culture was tested. Immunohistochemistry and quantitative reverse transcriptase–polymerase chain reaction analyses were utilized to assess the expression of collagen type I, collagen type II, and collagen type X throughout the time studied. We found expression of all the markers as early as 4 days of chondrogenic differentiation culture, with their expression increasing with time, except for collagen type I, which decreased in expression in the formed spheroids after 4 days of differentiation. The signaling role of Wnt during chondrogenic differentiation was studied by western blot. We observed that ÎČ-catenin expression decreased during the chondrogenic process. Further, a secretome study to validate our model of differentiation in vitro was performed on spheroids formed during the chondrogenesis process. Our results indicate the multipotential capacity of this source of human cells; their chondrogenic capacity could be useful for future cell therapy in articular diseases.Servizo Galego de SaĂșde; PS07=8
    • 

    corecore