710 research outputs found
Is exponential gravity a viable description for the whole cosmological history?
Here we analysed a particular type of gravity, the so-called
exponential gravity which includes an exponential function of the Ricci scalar
in the action. Such term represents a correction to the usual Hilbert-Einstein
action. By using Supernovae Ia, Barionic Acoustic Oscillations, Cosmic
Microwave Background and data, the free parameters of the model are well
constrained. The results show that such corrections to General Relativity
become important at cosmological scales and at late-times, providing an
alternative to the dark energy problem. In addition, the fits do not determine
any significant difference statistically with respect to the CDM
model. Finally, such model is extended to include the inflationary epoch in the
same gravitational Lagrangian. As shown in the paper, the additional terms can
reproduce the inflationary epoch and satisfy the constraints from Planck data.Comment: 20 pages, 6 figures, analysis extended, version published in EPJ
Effectiveness of an Eye-Cervical Re-Education Program in Chronic Neck Pain: A Randomized Clinical Trial
Objectives. Proprioceptive training is popularly applied as a therapeutic exercise method in physiotherapy. Its effects on pain and range of motion are only poorly evaluated. Therefore, this study assesses the effectiveness of proprioceptive training with an Eye-Cervical Re-education Program to decrease pain and increase the joint range in chronic neck pain patients. Material and Methods. Design. A randomized, no-blinded, controlled clinical trial. Setting. Physiotherapy consultation. Participants. 44 people were divided into two groups. Interventions. All patients were treated with a multimodal physiotherapy intervention. The experimental group was supplemented with an exercise program that included eye-cervical proprioception. Outcomes. The primary outcomes included pain pressure thresholds (upper trapezius, levator scapulae, and splenius capitis) and cervical range of motion. The secondary outcomes included pain measured by the Visual Analogical Scale and the McGillSpv Questionnaire. Results. The proprioception treatment was effective in reducing the pain pressure threshold in the right upper trapezius (p=0.001), left upper trapezius (p=0.014), right levator scapula (p=0.040), and left splenius capitis (p=0.021). The increase in the joint range was statistically significant (p<0.05) in favor of the Eye-Cervical Re-education Program for all movements assessed. Conclusions. The Eye-Cervical Re-education Program is effective at relieving pain pressure thresholds in the upper trapezius, right levator scapula, and left splenius capitis and especially effective for increasing the cervical range of motion. This trial is registered with (retrospective registration)
Regularizing Rotating Black Strings: a new black bounce solution
The present paper is devoted to a new black bounce solution that regularize
the well-known rotating black string in dimensions. To do so, the
procedure pointed out by Simpson-Visser is followed, which has been already
applied successfully to other static cases of black strings, with and without
electric charge. This method implies to force a bounce on the radial
coordinate, such that a wormhole throat arises before the singularity, which
renders a regular solution. An analysis of the metric is conducted, showing the
interpolation between a regular black hole and a wormhole, what provides a much
richer family of solutions than the original metric. Different curvature
magnitudes are obtained in order to analyze the regularity of the solution,
including the Ricci and Kretschmann scalars. Finally, by following the Einstein
field equations the corresponding effective energy-momentum tensor is obtained
and the energy conditions are analyzed.Comment: 8 page
PolyPurine Reverse Hoogsteen Hairpins Work as RNA Species for Gene Silencing
Adenovirus; Terapia contra el cáncer; Vectores viralesAdenovirus; Cancer therapy; Viral vectorsAdenovirus; Teràpia contra el càncer; Vectors viralsPolyPurine Reverse Hoogsteen Hairpins (PPRHs) are gene-silencing DNA-oligonucleotides developed in our laboratory that are formed by two antiparallel polypurine mirror repeat domains bound intramolecularly by Hoogsteen bonds. The aim of this work was to explore the feasibility of using viral vectors to deliver PPRHs as a gene therapy tool. After treatment with synthetic RNA, plasmid transfection, or viral infection targeting the survivin gene, viability was determined by the MTT assay, mRNA was determined by RT-qPCR, and protein levels were determined by Western blot. We showed that the RNA-PPRH induced a decrease in cell viability in a dose-dependent manner and an increase in apoptosis in PC-3 and HeLa cells. Both synthetic RNA-PPRH and RNA-PPRH intracellularly generated upon the transfection of a plasmid vector were able to reduce survivin mRNA and protein levels in PC-3 cells. An adenovirus type-5 vector encoding the PPRH against survivin was also able to decrease survivin mRNA and protein levels, leading to a reduction in HeLa cell viability. In this work, we demonstrated that PPRHs can also work as RNA species, either chemically synthesized, transcribed from a plasmid construct, or transcribed from viral vectors. Therefore, all these results are the proof of principle that viral vectors could be considered as a delivery system for PPRHs.This research was funded by grant RTI2018-093901-B-I00 from Plan Nacional de Investigación Científica (Spain). Group holding the Quality Mention from Generalitat de Catalunya 2017-SGR-94. EA is awarded with fellowships from Generalitat de Catalunya (FI)
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