Extensive reuse of soda-lime waste glass in fly ash-based geopolymers

The possibility of extensive incorporation of soda-lime waste glass in the synthesis of fly ash-based geopolymers was investigated. Using waste glass as silica supplier avoids the use of water glass solution as chemical activator. The influence of the addition of waste glass on the microstructure and strength of fly ash-based geopolymers was studied through microstructural and mechanical characterization. Leaching analyses were also carried out. The samples were developed changing the SiO2/Al2O3 molar ratio and the molarity of the sodium hydroxide solution used as alkaline activator. The results suggest that increasing the amount of waste glass as well as increasing the molarity of the solution lead to the formation of zeolite crystalline phases and an improvement of the mechanical strength. Leaching results confirmed that the new geopolymers have the capability to immobilize heavy metal ions

Seizures

Seizures are common in intensive care patients generally. Cardiac surgery or post-cardiac arrest patients are at particular risk of brain injury. Seizures are an important and potentially reversible cause of prolonged unconsciousness as well as being associated with poorer ICU outcome, although the latter may be multifactorial. Cerebral metabolic rate is greatly increased during seizure activity that may lead to energetic crisis and neuronal injury. Non-convulsive seizures are particularly common in ICU patients and are therefore under-recognised. Electroencephalography (EEG) is therefore an essential ICU investigation the diagnosis of seizures, epileptiform activity and for distinguishing these from other disorders of consciousness, which may have characteristic EEG signatures. Continuous EEG is particularly sensitive for clinically occult seizures and is also helpful for managing seizures refractory to simple treatment. However EEG requires specific expertise to perform and interpret which can be a barrier to its use

Galactic Outflows and the pollution of the Galactic Environment by Supernovae

We here explore the effects of the SN explosions into the environment of star-forming galaxies like the Milky Way. Successive randomly distributed and clustered SNe explosions cause the formation of hot superbubbles that drive either fountains or galactic winds above the galactic disk, depending on the amount and concentration of energy that is injected by the SNe. In a galactic fountain, the ejected gas is re-captured by the gravitational potential and falls back onto the disk. From 3D nonequilibrium radiative cooling hydrodynamical simulations of these fountains, we find that they may reach altitudes up to about 5 kpc in the halo and thus allow for the formation of the so called intermediate-velocity-clouds (IVCs) which are often observed in the halos of disk galaxies. The high-velocity-clouds that are also observed but at higher altitudes (of up to 12 kpc) require another mechanism to explain their production. We argue that they could be formed either by the capture of gas from the intergalactic medium and/or by the action of magnetic fields that are carried to the halo with the gas in the fountains. Due to angular momentum losses to the halo, we find that the fountain material falls back to smaller radii and is not largely spread over the galactic disk. Instead, the SNe ejecta fall nearby the region where the fountain was produced, a result which is consistent with recent chemical models of the galaxy. The fall back material leads to the formation of new generations of molecular clouds and to supersonic turbulence feedback in the disk.Comment: 10 pages, 5 figures; paper of invited talk for the Procs. of the 2007 WISER Workshop (World Space Environment Forum), Alexandria, Egypt, October 2007, Spa. Sci. Rev

Multifrequency acoustics as a probe of mesoscopic blood coagulation dynamics

Coagulation is a complex enzymatic polymerisation cascade. Disordered coagulation is common in medicine and may be life-threatening yet clinical assays are typically bulky and/or provide an incomplete picture of clot mechanical evolution. We present the adaptation of an in-plane acoustic wave device: quartz crystal microbalance with dissipation at multiple harmonics to determine the time-evolution of mesoscale mechanical properties of clot formation in vitro. This approach is sensitive to changes in surface and bulk clot structure in various models of induced coagulopathy. Furthermore, we are able to show that clot formation at surfaces has different kinetics and mechanical strength to that in the bulk, which may have implications for the design of bioprosthetic materials. The “Multifrequency acoustics” approach thus enables unique capability to portray biological processes concerning blood coagulation.Funding from the Cambridge University Engineering for Clinical Practice initiative and the Cambridge Trusts is gratefully acknowledged.This is the author accepted manuscript. The final version is available from AIP at http://dx.doi.org/10.1063/1.4960978

Performance of cardiopulmonary exercise testing for the prediction of post-operative complications in non cardiopulmonary surgery: A systematic review

Funder: Wellcome Trust; funder-id: http://dx.doi.org/10.13039/100010269; Grant(s): Clinician PhD Fellowship paid from [Overarching grant: 486 204017/Z/16/ZIntroduction: Cardiopulmonary exercise testing (CPET) is widely used within the United Kingdom for preoperative risk stratification. Despite this, CPET’s performance in predicting adverse events has not been systematically evaluated within the framework of classifier performance. Methods: After prospective registration on PROSPERO (CRD42018095508) we systematically identified studies where CPET was used to aid in the prognostication of mortality, cardiorespiratory complications, and unplanned intensive care unit (ICU) admission in individuals undergoing non-cardiopulmonary surgery. For all included studies we extracted or calculated measures of predictive performance whilst identifying and critiquing predictive models encompassing CPET derived variables. Results: We identified 36 studies for qualitative review, from 27 of which measures of classifier performance could be calculated. We found studies to be highly heterogeneous in methodology and quality with high potential for bias and confounding. We found seven studies that presented risk prediction models for outcomes of interest. Of these, only four studies outlined a clear process of model development; assessment of discrimination and calibration were performed in only two and only one study undertook internal validation. No scores were externally validated. Systematically identified and calculated measures of test performance for CPET demonstrated mixed performance. Data was most complete for anaerobic threshold (AT) based predictions: calculated sensitivities ranged from 20-100% when used for predicting risk of mortality with high negative predictive values (96-100%). In contrast, positive predictive value (PPV) was poor (2.9-42.1%). PPV appeared to be generally higher for cardiorespiratory complications, with similar sensitivities. Similar patterns were seen for the association of Peak VO2 (sensitivity 85.7-100%, PPV 2.7-5.9%) and VE/VCO2 (Sensitivity 27.8%-100%, PPV 3.4-7.1%) with mortality. Conclusions: In general CPET’s ‘rule-out’ capability appears better than its ability to ‘rule-in’ complications. Poor PPV may reflect the frequency of complications in studied populations. Our calculated estimates of classifier performance suggest the need for a balanced interpretation of the pros and cons of CPET guided pre-operative risk stratification

Organizational health and quality of life: survey among ambulance nurses in prehospital emergency care

Background: The workplace plays a central role in causing stress and different kinds of syndromes and diseases. More generally, organizational procedures and practices could have an impact on nurses’ quality of life. Although several studies have investigated this link, none of them considered nurses working in prehospital emergency care. Objectives: To investigate the role of organizational health factors that affect the quality of life and psychosomatic complaints of ambulance nurses.Method: Our sample included 411 ambulance nurses. Workers were administered two questionnaires to assess organizational health and quality of life. Descriptive and correlational analyses were used to test our assumptions. Conclusion: Several organizational health dimensions provided an explanation for the complaints reported by nurses working in prehospital emergency care in terms of quality of life and psychosomatic disorders.The results allowed identification of possible interventions focusing on specific duties and organizational aspects that would improve the quality of nurses’ health

Resuscitation of patients with active Do Not Attempt Cardiopulmonary Resuscitation (DNACPR) status after out-of-hospital cardiac arrest.

Victims of out-of-hospital cardiac arrest (OHCA) will often already be living with serious or life- threatening chronic co-morbidities. Many patients express wishes that they would not want to be resuscitated in the event of a cardiac arrest. Analysis of calls to Compassion in Dying’s End- of-Life Rights Information Line demonstrated public concerns about being resuscitated against their wishes [1]. Nevertheless resuscitation of patients with Do Not Attempt Cardiopulmonary Resuscitation (DNACPR) decisions does sometimes occur in the hospital setting [2]

Variation between countries in the frequency of diabetic ketoacidosis at first presentation of type 1 diabetes in children: a systematic review.

AIMS/HYPOTHESIS: Type 1 diabetes is the most frequent endocrine disease in children, with 65,000 children diagnosed worldwide every year. Up to 80% of these children present with diabetic ketoacidosis (DKA), which is associated with both short-term risks and long-term consequences. This study aimed to characterise the worldwide variation in presentation of type 1 diabetes to inform future interventions to reduce this excess morbidity and mortality. METHODS: This was a systematic review of studies indexed on PubMed, EMBASE, Web of Science, Scopus or CINAHL before March 2011 that included unselected groups of children presenting with new-onset type 1 diabetes, reported the proportion presenting with DKA and used a definition of DKA based on measurement of pH or bicarbonate. RESULTS: Sixty-five studies of cohorts comprising over 29,000 children in 31 countries were included. The frequency of DKA at diagnosis ranged from 12.8% to 80%, with highest frequencies in the United Arab Emirates, Saudi Arabia and Romania, and the lowest in Sweden, the Slovak Republic and Canada. Multivariable modelling showed the frequency of DKA was inversely associated with gross domestic product, latitude and background incidence of type 1 diabetes. CONCLUSIONS/INTERPRETATION: This is the first description of the variation in frequency of DKA at presentation of type 1 diabetes in children across countries. It demonstrates large variations that may, at least in part, be explained by different levels of disease awareness and healthcare provision and suggests ways to decrease the excess morbidity and mortality associated with DKA at diagnosis

Supuestos del modelo de inventarios

Existe un modelo clásico para la determinación del lote económicamente óptimo de compra o producción de insumos o productos. El modelo parte del conocimiento de la demanda, del costo de compra o producción, del costo del producto en cuestión y del costo de tenencia del mismo. Una vez determinado dicho lote óptimo se concluye que el mismo lleva a un nivel óptimo de inventarios pues minimiza el costo total de administración del stock. Sin embargo, el modelo asume una serie de supuestos que es conveniente analizar para descubrir si es posible flexibilizar los mismos con el objetivo de lograr una aplicación del modelo en las Organizaciones con una óptica más realista. Desde ya que los supuestos no invalidan el modelo y es claramente posible una adecuada administración, al menos en sus premisas básicas, con los procedimientos desarrollados en esta temática. El análisis adicional propuesto en el presente trabajo es el examen de dichos supuestos o limitaciones subyacentes de las técnicas y procedimientos con el objetivo de permitir una administración eficaz de los niveles de inventarios, sean éstos de insumos o de productos terminados.publishedVersionFil: Ercole, Raúl A. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Ercole, Raúl A. Universidad Católica de Córdoba; Argentina.Negocios y Administració