495 research outputs found

    Towards understanding the myometrial physiome: approaches for the construction of a virtual physiological uterus

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    Premature labour (PTL) is the single most significant factor contributing to neonatal morbidity in Europe with enormous attendant healthcare and social costs. Consequently, it remains a major challenge to alleviate the cause and impact of this condition. Our ability to improve the diagnosis and treatment of women most at risk of PTL is, however, actually hampered by an incomplete understanding of the ways in which the functions of the uterine myocyte are integrated to effect an appropriate biological response at the multicellular whole organ system. The level of organization required to co-ordinate labouring uterine contractile effort in time and space can be considered immense. There is a multitude of what might be considered mini-systems involved, each with their own regulatory feedback cycles, yet they each, in turn, will influence the behaviour of a related system. These include, but are not exclusive to, gestational-dependent regulation of transcription, translation, post-translational modifications, intracellular signaling dynamics, cell morphology, intercellular communication and tissue level morphology. We propose that in order to comprehend how these mini-systems integrate to facilitate uterine contraction during labour (preterm or term) we must, in concert with biological experimentation, construct detailed mathematical descriptions of our findings. This serves three purposes: firstly, providing a quantitative description of series of complex observations; secondly, proferring a database platform that informs further testable experimentation; thirdly, advancing towards the establishment of a virtual physiological uterus and in silico clinical diagnosis and treatment of PTL

    Alkaline activation of ceramic waste materials

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    Ceramic materials represent around 45 % of construction and demolition waste, and originate not only from the building process, but also as rejected bricks and tiles from industry. Despite the fact that these wastes are mostly used as road sub-base or construction backfill materials, they can also be employed as supplementary cementitious materials, or even as raw material for alkali-activated binders This research aimed to investigate the properties and microstructure of alkali-activated cement pastes and mortars produced from ceramic waste materials of various origins. Sodium hydroxide and sodium silicate were used to prepare the activating solution. The compressive strength of the developed mortars ranged between 22 and 41 MPa after 7 days of curing at 65 C, depending on the sodium concentration in the solution and the water/binder ratio. These results demonstrate the possibility of using alkaliactivated ceramic materials in building applications.The authors are grateful to the Spanish Ministry of Science and Innovation for supporting this study through Project GEOCEDEM BIA 2011-26947, and also to FEDER funding. They also thank Universitat Jaume I for supporting this research through Lucia Reig's granted research stay.Reig Cerdá, L.; Mitsuuchi Tashima, M.; Soriano, L.; Borrachero Rosado, MV.; Monzó Balbuena, JM.; Paya Bernabeu, JJ. (2013). Alkaline activation of ceramic waste materials. Waste and Biomass Valorization. 4:729-736. https://doi.org/10.1007/s12649-013-9197-zS7297364Puertas, F., García-Díaz, I., Barba, A., Gazulla, M.F., Palacios, M., Gómez, M.P., Martínez-Ramírez, S.: Ceramic wastes as alternative raw materials for Portland cement clinker production. Cement Concrete Comp. 30(9), 798–805 (2008)Ministerio de Fomento de España, Catálogo de Residuos Utilizables en Construcción (2010). http://www.cedexmateriales.vsf.es/view/catalogo.aspx . Retrieved on 6 Dec 2012Stock, D.: World production and consumption of ceramic tiles. Tile Today 73, 50–58 (2011)Medina, C., Juan, A., Frías, M., Sánchez-de-Rojas, M.I., Morán, J.M., Guerra, M.I.: Characterization of concrete made with recycled aggregate from ceramic sanitary ware. Mater. Construcc. 61(304), 533–546 (2011)Pacheco-Torgal, F., Jalali, S.: Reusing ceramic wastes in concrete. Constr. Build. Mater. 24(5), 832–838 (2010)Lavat, A.E., Trezza, M.A., Poggi, M.: Characterization of ceramic roof tile wastes as pozzolanic admixture. Waste Manage. 29(5), 1666–1674 (2009)Nuran, A., Mevlut, U.: The use of waste ceramic tile in cement production. Cement Concrete Res. 30, 497–499 (2000)Pereira-de-Oliveira, L.A., Castro-Gomes, J.P., Santos, P.M.S.: The potential pozzolanic activity of glass and red-clay ceramic waste as cement mortars components. Constr. Build. Mater. 31, 197–203 (2012)Van Deventer, J.S.J., Provis, J.L., Duxson, P., Brice, D.G.: Chemical research and climate change as drivers in the commercial adoption of alkali activated materials. Waste Biomass Valor. 1, 145–155 (2010)van Deventer, J.S.J., Provis, J.L., Duxson, P., Lukey, G.C.: Reaction mechanisms in the geopolymeric conversion of inorganic waste to useful products. J. Hazard. Mater. A139, 506–513 (2007)Duxson, P., Fernández-Jiménez, A., Provis, J.L., Lukey, G.C., Palomo, A., van Deventer, J.S.J.: Geopolymer technology: the current state of the art. J. Mater. Sci. 42(9), 2917–2993 (2007)Bernal, S.A., Rodríguez, E.D., de Gutiérrez, R.M., Provis, J.L., Delvasto, S.: Activation of metakaolin/slag blends using alkaline solutions based on chemically modified silica fume and rice husk ash. Waste Biomass Valor. 3, 99–108 (2012)Fernández-Jiménez, A., Palomo, A., Criado, M.: Microstructure development of alkali-activated fly ash cement: a descriptive model. Cement Concrete Res 35, 1204–1209 (2005)Payá, J., Borrachero, M.V., Monzó, J., Soriano, L., Tashima, M.M.: A new geopolymeric binder from hydrated-carbonated cement. Mater. Lett. 74, 223–225 (2012)Kourti, I., Amutha-Rani, D., Deegan, D., Boccaccini, A.R., Cheeseman, C.R.: Production of geopolymers using glass produced from DC plasma treatment of air pollution control (APC) residues. J. Hazard. Mater. 176, 704–709 (2010)Puertas, F., Barba, A., Gazulla, M.F., Gómez, M.P., Palacios, M., Martínez-Ramírez, S.: Residuos cerámicos para su posible uso como materia prima en la fabricación de clínker de cemento Portland: caracterización y activación alcalina. Mater. Construcc. 56(281), 73–84 (2006)Reig, L., Tashima, M.M., Borrachero, M.V., Monzó, J., Payá, J.: Nuevas matrices cementantes generadas por Activación Alcalina de residuos cerámicos. II Simposio Aprovechamiento de residuos agro-industriales como fuente sostenible de materiales de construcción, November 8–9, Valencia, Spain, pp. 199–207 (2010)L. Reig, M.M. Tashima, M.V. Borrachero, J. Monzó, J. Payá: Residuos de ladrillos cerámicos en la producción de conglomerantes activados alcalinamente, I Pro-Africa Conference: Non-conventional Building Materials Based on Agroindustrial Wastes, October 18–19, Pirassununga, SP, Brazil, pp. 18–21 (2010)García Ten F.J. Descomposición durante la cocción del carbonato cálcico contenido en el soporte crudo de los azulejos. Tesis de doctorado, Departamento de Ingeniería química, UJI (2005)Baronio, G., Binda, L.: Study of the pozzolanicity of some bricks and clays. Constr. Build. Mater. 11(1), 41–46 (1997)Zanelli, C., Raimondo, M., Guarini, G., Dondi, M.: The vitreous phase of porcelain stoneware: composition, evolution during sintering and physical properties. J. Non-Cryst. Solids 357, 3251–3260 (2011)Carty, W.M., Senapati, U.: Porcelain-raw materials, processing, phase evolution, and mechanical behaviour. J. Am. Ceram. Soc. 81(1), 3–20 (1998)ASCER, COACV, COPUT, ITC-AICE, WEBER ET BROUTIN – CEMARKSA: Guía Baldosa Guía de la baldosa cerámica. IVE: Conselleria d’Obres Públiques, Urbanisme i Transports, 4ª Ed. Valencia (2003)Khater, H.M.: Effect of calcium on geopolimerization of aluminosilicate wastes. J. Mater. Civ. Eng. 24, 92–101 (2012)Bondar, D., Lynsdale, C.J., Milestone, N.B., Hassani, N., Ramezanianpour, A.A.: Effect of adding mineral additives to alkali-activated natural pozzolan paste. Constr. Build. Mater. 25, 2906–2910 (2011)Provis, J.L., Harrex, R.M., Bernal, A.S., Duxson, P., van Deventer, J.S.J.: Dilatometry of geopolymers as a means of selecting desirable fly ash sources. J. Non-Cryst. Solids 358, 1930–1937 (2012)Duxson, P., Provis, J.L., Lukey, G.C., Mallicoat, S.W., Kriven, W.M., van Deventer, J.S.J.: Understanding the relationship between geopolymer composition, microstructure and mechanical properties. Colloid Surf. A 269, 47–58 (2005)Tashima, M.M., Akasaki, J.L., Castaldelli, V.N., Soriano, L., Monzó, J., Payá, J., Borrachero, M.V.: New geopolymeric binder based on fluid catalytic cracking catalyst residue (FCC). Mater. Lett. 80, 50–52 (2012)Komnitsas, K., Zaharaki, D., Perdikatsis, V.: Geopolymerisation of low calcium ferronickel slags. J. Mater. Sci. 42, 3073–3082 (2007)Bernal, S.A., Gutierrez, R.M., Provis, J.L., Rose, V.: Effect of silicate modulus and metakaolin incorporation on the carbonation of alkali silicate-activated slags. Cement Concrete Res. 40, 898–907 (2010)Tashima, M.M. Produccion y caracterizacion de materiales cementantes a partir del silicoaluminato calcico vitreo (VCAS). Tesis de doctorado, Departamento de Ingeniería de la construcción y de proyectos de ingeniería civil, UPV (2012)Provis, J.L., van Deventer, J.S.J.: Geopolymerisation kinetics. 2. Reaction kinetic modelling. Chem. Eng. Sci. 62, 2318–2329 (2007

    Why alternative teenagers self-harm: exploring the link between non-suicidal self-injury, attempted suicide and adolescent identity

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    Background: The term ‘self-harm’ encompasses both attempted suicide and non-suicidal self-injury (NSSI). Specific adolescent subpopulations such as ethnic or sexual minorities, and more controversially, those who identify as ‘Alternative’ (Goth, Emo) have been proposed as being more likely to self-harm, while other groups such as ‘Jocks’ are linked with protective coping behaviours (for example exercise). NSSI has autonomic (it reduces negative emotions) and social (it communicates distress or facilitates group ‘bonding’) functions. This study explores the links between such aspects of self-harm, primarily NSSI, and youth subculture.<p></p> Methods: An anonymous survey was carried out of 452 15 year old German school students. Measures included: identification with different youth cultures, i.e. Alternative (Goth, Emo, Punk), Nerd (academic) or Jock (athletic); social background, e.g. socioeconomic status; and experience of victimisation. Self-harm (suicide and NSSI) was assessed using Self-harm Behavior Questionnaire and the Functional Assessment of Self-Mutilation (FASM).<p></p> Results: An “Alternative” identity was directly (r ≈ 0.3) and a “Jock” identity inversely (r ≈ -0.1) correlated with self-harm. “Alternative” teenagers self-injured more frequently (NSSI 45.5% vs. 18.8%), repeatedly self-injured, and were 4–8 times more likely to attempt suicide (even after adjusting for social background) than their non-Alternative peers. They were also more likely to self-injure for autonomic, communicative and social reasons than other adolescents.<p></p> Conclusions: About half of ‘Alternative’ adolescents’ self-injure, primarily to regulate emotions and communicate distress. However, a minority self-injure to reinforce their group identity, i.e. ‘To feel more a part of a group’

    THG113.31, a specific PGF2alpha receptor antagonist, induces human myometrial relaxation and BKCa channel activation

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    BACKGROUND: PGF2alpha exerts a significant contractile effect on myometrium and is central to human labour. THG113.31, a specific non-competitive PGF2alpha receptor (FP) antagonist, exerts an inhibitory effect on myometrial contractility. The BKCa channel is ubiquitously encountered in human uterine tissue and plays a significant role in modulating myometrial cell membrane potential and excitability. The objective of this study was to investigate potential BKCa channel involvement in the response of human myometrium to THG113.31. METHODS: Single and whole-cell electrophysiological BKCa channel recordings from freshly dispersed myocytes, were investigated in the presence and absence of THG113.31. Functional studies investigated the effects of THG113.31 on isolated spontaneous myometrial contractions, in the presence and absence of the BKCa channel blocker, iberiotoxin. RESULTS: Single channel recordings identified the BKCa channel as a target of THG113.31. THG113.31 significantly increased the open state probability of these channels [control 0.023+/-0.006; 10 microM THG113.31 0.087+/-0.012 (P = 0.009); and 50 microM THG113.31 0.1356+/-0.018 (P = 0.001)]. In addition, THG113.31 increased whole-cell BKCa currents over a range of membrane potentials, and this effect was reversed by 100 nanoM IbTX. Isometric tension studies demonstrated that THG113.31 exerted a significant concentration-dependent relaxant effect on human myometrial tissue and pre-incubation of strips with IbTX abolished this effect on spontaneously occurring contractions. CONCLUSION: These data suggests that activation of the BKCa channel may contribute, at least partially, to the uterorelaxant effect of THG113.31

    Accreting Millisecond X-Ray Pulsars

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    Accreting Millisecond X-Ray Pulsars (AMXPs) are astrophysical laboratories without parallel in the study of extreme physics. In this chapter we review the past fifteen years of discoveries in the field. We summarize the observations of the fifteen known AMXPs, with a particular emphasis on the multi-wavelength observations that have been carried out since the discovery of the first AMXP in 1998. We review accretion torque theory, the pulse formation process, and how AMXP observations have changed our view on the interaction of plasma and magnetic fields in strong gravity. We also explain how the AMXPs have deepened our understanding of the thermonuclear burst process, in particular the phenomenon of burst oscillations. We conclude with a discussion of the open problems that remain to be addressed in the future.Comment: Review to appear in "Timing neutron stars: pulsations, oscillations and explosions", T. Belloni, M. Mendez, C.M. Zhang Eds., ASSL, Springer; [revision with literature updated, several typos removed, 1 new AMXP added

    Collaborative planning approach to inform the implementation of a healthcare manager intervention for hispanics with serious mental illness: a study protocol

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    Background: This study describes a collaborative planning approach that blends principles of community-based participatory research (CBPR) and intervention mapping to modify a healthcare manager intervention to a new patient population and provider group and to assess the feasibility and acceptability of this modified intervention to improve the physical health of Hispanics with serious mental illness (SMI) and at risk for cardiovascular disease (CVD). Methods: The proposed study uses a multiphase approach that applies CBPR principles and intervention-mapping steps--an intervention-planning approach--to move from intervention planning to pilot testing. In phase I, a community advisory board composed of researchers and stakeholders will be assembled to learn and review the intervention and make initial modifications. Phase II uses a combination of qualitative methods--patient focus groups and stakeholder interviews--to ensure that the modifications are acceptable to all stakeholders. Phase III uses results from phase II to further modify the intervention, develop an implementation plan, and train two care managers on the modified intervention. Phase IV consists of a 12-month open pilot study (N = 30) to assess the feasibility and acceptability of the modified intervention and explore its initial effects. Lastly, phase V consists of analysis of pilot study data and preparation for future funding to develop a more rigorous evaluation of the modified intervention. Discussion: The proposed study is one of the few projects to date to focus on improving the physical health of Hispanics with SMI and at risk for CVD by using a collaborative planning approach to enhance the transportability and use of a promising healthcare manager intervention. This study illustrates how blending health-disparities research and implementation science can help reduce the disproportionate burden of medical illness in a vulnerable population

    Hepatitis C infection: eligibility for antiviral therapies

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    peer reviewedBackground Current treatments of chronic hepatitis C virus (HCV) are effective, but expensive and susceptible to induce significant side effects. Objectives To evaluate the proportion of HCV patients who are eligible for a treatment. Methods In a database comprising 1726 viraemic HCV patients, the files of 299 patients who presented to the same hepatologist for an initial appointment between 1996 and 2003 were reviewed. Results Patients' characteristics were age 43.1 +/- 15.6 years, 53% male and 92% Caucasian. The main risk factors were transfusion (43%) and drug use (22%). Genotypes were mostly genotype 1 (66%), genotype 3 (12%) and genotype 2 (10%). These characteristics were not different from those of the whole series of 1726 patients. A total of 176 patients (59%) were not treated, the reasons for non-treatment being medical contraindications (34%), non-compliance (25%) and normal transaminases (24%). In addition, 17% of patients declined therapy despite being considered as eligible, mainly due to fear of adverse events. Medical contraindications were psychiatric (27%), age (22%), end-stage liver disease (15%), willingness for pregnancy (13%), cardiac contraindication (7%) and others (16%). Only 123 patients (41%) were treated. A sustained viral response was observed in 41%. The treatment was interrupted in 16% for adverse events. Conclusions The majority of HCV patients are not eligible for treatment. This implies that, with current therapies, only 17% of patients referred for chronic HCV become sustained responders. Some modifications of guidelines could extend the rate of treatment (patients with normal transaminases), but an important barrier remains the patients' and the doctors' fear of adverse events
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