53 research outputs found
Thermodynamical description of interacting entropy-corrected new agegraphic dark energy
To explain the accelerating universe driven by dark energy, a so-called
"entropy-corrected new agegraphic dark energy" (ECNADE), was recently proposed
with the help of quantum corrections to the entropy-area relation in the
framework of loop quantum cosmology. Using this definition, we study its
thermodynamical features including entropy and energy conservation. We discuss
the thermodynamical interpretation of the interaction between ECNADE and dark
matter in a non-flat universe bounded by the apparent horizon. We obtain a
relation between the interaction term of the dark components and thermal
fluctuation.Comment: 8 pages, version accepted for publication in Europhysics Letters
(2011
High performance fiber reinforced concrete for the shear reinforcement: experimental and numerical research
High performance fiber reinforced concrete (HPFRC) is developing rapidly to a modern structural material with
unique rheological and mechanical characteristics. Despite applying several methodologies to achieve self15
compacting requirements, some doubts still remain regarding the most convenient strategy for developing a
HPFRC. In the present study, an innovative mix design method is proposed for the development of high17
performance concrete reinforced with a relatively high dosage of steel fibers. The material properties of the
developed concrete are assessed, and the concrete structural behavior is characterized under compressive,
flexural and shear loading. This study better clarifies the significant contribution of fibers for shear resistance of
concrete elements.
This paper further discusses a FEM-based simulation, aiming to address the possibility of calibrating the
constitutive model parameters related to fracture modes I and II.The research in this paper is part of the project "DURCOST - Innovation in reinforcing systems for sustainable pre-fabricated structures of higher durability and enhanced structural performance" with reference number of PTDC/ECM/105700/2008, supported by FCT. The authors also thank the collaboration of the following companies: Casais to manufacture the moulds, Ibermetais for supplying the steel fibres, Secil/Unibetao for providing the Cement, BASF for supplying the superplasticizers. The first author acknowledges the research grant in the ambit of this project
Behaviour of GFRP-steel reinforced I shape beams with steel fibers as shear reinforcement
This paper evaluates the possibility of developing prefabricated beams without stirrups by
using fiber reinforcement for increasing the concrete shear capacity, and a hybrid flexural
reinforcement system composed of glass fiber reinforced polymer (GFPR) and steel rebars.
A high compressive strength and high post-cracking tensile capacity steel fiber reinforced
self-compacting concrete (SFRSCC) was developed, aiming at supressing the need of steel
stirrups in this type of beams while providing sufficient ductility for structural applications.
The experimental results were analysed in terms of failure mode, deformational and cracking
behaviour, as well as load carrying capacity. A constitutive model, capable of simulating
three types of material nonlinearities simultaneously in an integration point (IP), was used
and its predictive performance was assessed by simulating the experimental tests. The
numerical approach was then used to assess the potentialities of this material system and
structural concept when applied to relatively large span beams.The authors wish to acknowledge the funding provided by project FOATIDE, reference POCI-01-
0145-FEDER-028112
Psychedelics Promote Structural and Functional Neural Plasticity.
Atrophy of neurons in the prefrontal cortex (PFC) plays a key role in the pathophysiology of depression and related disorders. The ability to promote both structural and functional plasticity in the PFC has been hypothesized to underlie the fast-acting antidepressant properties of the dissociative anesthetic ketamine. Here, we report that, like ketamine, serotonergic psychedelics are capable of robustly increasing neuritogenesis and/or spinogenesis both in vitro and in vivo. These changes in neuronal structure are accompanied by increased synapse number and function, as measured by fluorescence microscopy and electrophysiology. The structural changes induced by psychedelics appear to result from stimulation of the TrkB, mTOR, and 5-HT2A signaling pathways and could possibly explain the clinical effectiveness of these compounds. Our results underscore the therapeutic potential of psychedelics and, importantly, identify several lead scaffolds for medicinal chemistry efforts focused on developing plasticity-promoting compounds as safe, effective, and fast-acting treatments for depression and related disorders
Interacting entropy-corrected new agegraphic dark energy in Brans-Dicke cosmology
Motivated by a recent work of one of us [1], we extend it by using quantum
(or entropy) corrected new agegraphic dark energy in the Brans-Dicke cosmology.
The correction terms are motivated from the loop quantum gravity which is one
of the competitive theories of quantum gravity. Taking the non-flat background
spacetime along with the conformal age of the universe as the length scale, we
derive the dynamical equation of state of dark energy and the deceleration
parameter. An important consequence of this study is the phantom divide
scenario with entropy-corrected new agegraphic dark energy. Moreover, we assume
a system of dark matter, radiation and dark energy, while the later interacts
only with dark matter. We obtain some essential expressions related with dark
energy dynamics. The cosmic coincidence problem is also resolved in our model.Comment: 16 pages, no figure, accepted for publication in Gen. Relativ. Gra
Heterozygous CAPN3 missense variants causing autosomal-dominant calpainopathy in seven unrelated families
[Aims] Recessive variants in CAPN3 gene are the cause of the commonest form of autosomal recessive limb girdle muscle dystrophy. However, two distinct in-frame deletions in CAPN3 (NM_000070.3:c.643_663del21 and c.598_621del15) and more recently, Gly445Arg and Arg572Pro substitutions have been linked to autosomal dominant (AD) forms of calpainopathy. We report 21 affected individuals from seven unrelated families presenting with an autosomal dominant form of muscular dystrophy associated with five different heterozygous missense variants in CAPN.[Methods] We have used massively parallel gene sequencing (MPS) to determine the genetic basis of a dominant form of limb girdle muscular dystrophy in affected individuals from seven unrelated families.[Results] The c.700G> A, [p.(Gly234Arg)], c.1327T> C [p.(Ser443Pro], c.1333G> A [p.(Gly445Arg)], c.1661A> C [p.(Tyr554Ser)] and c.1706T> C [p.(Phe569Ser)] CAPN3 variants were identified. Affected individuals presented in young adulthood with progressive proximal and axial weakness, waddling walking and scapular winging or with isolated hyperCKaemia. Muscle imaging showed fatty replacement of paraspinal muscles, variable degrees of involvement of the gluteal muscles, and the posterior compartment of the thigh and minor changes at the mid-leg level. Muscle biopsies revealed mild myopathic changes. Western blot analysis revealed a clear reduction in calpain 3 in skeletal muscle relative to controls. Protein modelling of these variants on the predicted structure of calpain 3 revealed that all variants are located in proximity to the calmodulin-binding site and are predicted to interfere with proteolytic activation.[Conclusions] We expand the genotypic spectrum of CAPN3-associated muscular dystrophy due to autosomal dominant missense variants.This study was funded in part by Instituto de Salud Carlos III through the project PI14/00738 to M. O. (co-funded by European Regional Development Fund. ERDF, a way to build Europe). We thank CERCA Programme / Generalitat de Catalunya for institutional support NGL (APP1117510) and GR (APP1122952) are supported by the Australian National Health and Medical Research Council (NHMRC). This work is also funded by an NHMRC Project Grant (APP1080587).Peer reviewe
Gabapentin for the hemodynamic response to intubation: systematic review and meta-analysis
Purpose
Endotracheal intubation is the gold standard for securing the airway before surgery. Nevertheless, this procedure can produce an activation of the sympathetic nervous system and result in a hemodynamic response which, in high-risk patients, may lead to cardiovascular instability and myocardial ischemia. The aim of this review was to evaluate whether gabapentin can attenuate this response and whether such an attenuation could translate into reduced myocardial ischemia and mortality.
Source
We searched MEDLINE®, EMBASE™, CINAHL, AMED, and unpublished clinical trial databases for randomized-controlled trials that compared gabapentin with control, fentanyl, clonidine, or beta blockers for attenuating the hemodynamic response to intubation. Primary outcomes were mortality, myocardial infarction, and myocardial ischemia. Secondary outcomes were hemodynamic changes following intubation.
Principal findings
We included 29 randomized trials with only two studies at low risk of bias. No data were provided for the primary outcomes and no studies included high-risk patients. The use of gabapentin resulted in attenuation in the rise in mean arterial blood pressure [mean difference (MD), −12 mmHg; 95% confidence interval (CI), −17 to −8] and heart rate (MD, −8 beats·min−1; 95% CI, −11 to −5) one minute after intubation. Gabapentin also reduced the risk of hypertension or tachycardia requiring treatment (risk ratio, 0.15; 95% CI, 0.05 to 0.48). Data were limited on adverse hemodynamic events such as bradycardia and hypotension.
Conclusion
It remains unknown whether gabapentin improves clinically relevant outcomes such as death and myocardial infarction since studies failed to report on these. Nevertheless, gabapentin attenuated increases in heart rate and blood pressure following intubation when compared with the control group. Even so, the studies included in this review were at potential risk of bias. Moreover, they did not include high-risk patients or report adverse hemodynamic outcomes. Future studies are required to address these limitations
The Geomechanics of CO2 Storage in Deep Sedimentary Formations
This paper provides a review of the geomechanics and modeling of geomechanics associated with geologic carbon storage (GCS), focusing on storage in deep sedimentary formations, in particular saline aquifers. The paper first introduces the concept of storage in deep sedimentary formations, the geomechanical processes and issues related with such an operation, and the relevant geomechanical modeling tools. This is followed by a more detailed review of geomechanical aspects, including reservoir stress-strain and microseismicity, well integrity, caprock sealing performance, and the potential for fault reactivation and notable (felt) seismic events. Geomechanical observations at current GCS field deployments, mainly at the In Salah CO2 storage project in Algeria, are also integrated into the review. The In Salah project, with its injection into a relatively thin, low-permeability sandstone is an excellent analogue to the saline aquifers that might be used for large scale GCS in parts of Northwest Europe, the U.S. Midwest, and China. Some of the lessons learned at In Salah related to geomechanics are discussed, including how monitoring of geomechanical responses is used for detecting subsurface geomechanical changes and tracking fluid movements, and how such monitoring and geomechanical analyses have led to preventative changes in the injection parameters. Recently, the importance of geomechanics has become more widely recognized among GCS stakeholders, especially with respect to the potential for triggering notable (felt) seismic events and how such events could impact the long-term integrity of a CO{sub 2} repository (as well as how it could impact the public perception of GCS). As described in the paper, to date, no notable seismic event has been reported from any of the current CO{sub 2} storage projects, although some unfelt microseismic activities have been detected by geophones. However, potential future commercial GCS operations from large power plants will require injection at a much larger scale. For such largescale injections, a staged, learn-as-you-go approach is recommended, involving a gradual increase of injection rates combined with continuous monitoring of geomechanical changes, as well as siting beneath a multiple layered overburden for multiple flow barrier protection, should an unexpected deep fault reactivation occur
EMQN best practice guidelines for genetic testing in dystrophinopathies.
Dystrophinopathies are X-linked diseases, including Duchenne muscular dystrophy and Becker muscular dystrophy, due to DMD gene variants. In recent years, the application of new genetic technologies and the availability of new personalised drugs have influenced diagnostic genetic testing for dystrophinopathies. Therefore, these European best practice guidelines for genetic testing in dystrophinopathies have been produced to update previous guidelines published in 2010.These guidelines summarise current recommended technologies and methodologies for analysis of the DMD gene, including testing for deletions and duplications of one or more exons, small variant detection and RNA analysis. Genetic testing strategies for diagnosis, carrier testing and prenatal diagnosis (including non-invasive prenatal diagnosis) are then outlined. Guidelines for sequence variant annotation and interpretation are provided, followed by recommendations for reporting results of all categories of testing. Finally, atypical findings (such as non-contiguous deletions and dual DMD variants), implications for personalised medicine and clinical trials and incidental findings (identification of DMD gene variants in patients where a clinical diagnosis of dystrophinopathy has not been considered or suspected) are discussed
Surgical treatment of pulmonary aspergilloma.
Fourteen patients with aspergilloma (fungus ball) were reviewed. Hemoptysis was the major symptom (93%). Chest roentgenograms disclosed a "fungus ball" in every patient, and the mycelia of Aspergillus fumigatus were recovered from all resected specimens. One of three patients treated by pneumonectomy died post-operatively. A lobectomy was performed in ten patients, and segmental resection in one without mortality or significant morbidity. There has been no evidence of recurrence in a follow up of six months to ten years. On the basis of this experience and a review of the literature, excision of a solitary "fungus ball" is recommended when the diagnosis is made. Non-surgical therapy should be reserved for patients whose general medical status or pulmonary reserved prohibit resection
- …