1,968 research outputs found
Regular (2+1)-dimensional black holes within non-linear Electrodynamics
(2+1)-regular static black hole solutions with a nonlinear electric field are
derived. The source to the Einstein equations is an energy momentum tensor of
nonlinear electrodynamics, which satisfies the weak energy conditions and in
the weak field limit becomes the (2+1)-Maxwell field tensor. The derived class
of solutions is regular; the metric, curvature invariants and electric field
are regular everywhere. The metric becomes, for a vanishing parameter, the
(2+1)-static charged BTZ solution. A general procedure to derive solutions for
the static BTZ (2+1)-spacetime, for any nonlinear Lagrangian depending on the
electric field is formulated; for relevant electric fields one requires the
fulfillment of the weak energy conditions.Comment: 5 pages, Latex, 2 figure
Size-Dependent passivation shell and magnetic properties in antiferromagnetic/ferrimagnetic core/shell MnO nanoparticles
The magnetic properties of bimagnetic core/shell nanoparticles consisting of an antiferromagnetic MnO core and a ferrimagnetic passivation shell have been investigated. It is found that the phase of the passivation shell (Îł-Mn2O3 or Mn3O4) depends on the size of the nanoparticles. Structural and magnetic characterizations concur that while the smallest nanoparticles have a predominantly Îł-Mn2O3 shell, larger ones have increasing amounts of Mn3O4. A considerable enhancement of the NĂŠel temperature, TN, and the magnetic anisotropy of the MnO core for decreasing core sizes has been observed. The size reduction also leads to other phenomena such as persistent magnetic moment in MnO up to high temperatures and an unusual temperature behavior of the magnetic domains
Effect of microalga Spirulina platensis (Arthrospira platensis) on hippocampus lipoperoxidation and lipid profile in rats with induced hypercholesterolemia
Un examen actualizado de la percepciĂłn de las barreras para la implementaciĂłn de la farmacogenĂłmica y la utilidad de los pares fĂĄrmaco/gen en AmĂŠrica Latina y el Caribe
La farmacogenĂłmica (PGx) se considera un campo emergente en los paĂses en desarrollo. La investigaciĂłn sobre PGx en la regiĂłn de AmĂŠrica Latina y el Caribe (ALC) sigue siendo escasa, con informaciĂłn limitada en algunas poblaciones. Por lo tanto, las extrapolaciones son complicadas, especialmente en poblaciones mixtas. En este trabajo, revisamos y analizamos el conocimiento farmacogenĂłmico entre la comunidad cientĂfica y clĂnica de ALC y examinamos las barreras para la aplicaciĂłn clĂnica. Realizamos una bĂşsqueda de publicaciones y ensayos clĂnicos en este campo en todo el mundo y evaluamos la contribuciĂłn de ALC. A continuaciĂłn, realizamos una encuesta regional estructurada que evaluĂł una lista de 14 barreras potenciales para la aplicaciĂłn clĂnica de biomarcadores en funciĂłn de su importancia. AdemĂĄs, se analizĂł una lista emparejada de 54 genes/fĂĄrmacos para determinar una asociaciĂłn entre los biomarcadores y la respuesta a la medicina genĂłmica. Esta encuesta se comparĂł con una encuesta anterior realizada en 2014 para evaluar el progreso en la regiĂłn. Los resultados de la bĂşsqueda indicaron que los paĂses de AmĂŠrica Latina y el Caribe han contribuido con el 3,44% del total de publicaciones y el 2,45% de los ensayos clĂnicos relacionados con PGx en todo el mundo hasta el momento. Un total de 106 profesionales de 17 paĂses respondieron a la encuesta. Se identificaron seis grandes grupos de obstĂĄculos. A pesar de los continuos esfuerzos de la regiĂłn en la Ăşltima dĂŠcada, la principal barrera para la implementaciĂłn de PGx en ALC sigue siendo la misma, la "necesidad de directrices, procesos y protocolos para la aplicaciĂłn clĂnica de la farmacogenĂŠtica/farmacogenĂłmica". Las cuestiones de coste-eficacia se consideran factores crĂticos en la regiĂłn. Los puntos relacionados con la reticencia de los clĂnicos son actualmente menos relevantes. SegĂşn los resultados de la encuesta, los pares gen/fĂĄrmaco mejor clasificados (96%-99%) y percibidos como importantes fueron CYP2D6/tamoxifeno, CYP3A5/tacrolimus, CYP2D6/opioides, DPYD/fluoropirimidinas, TMPT/tiopurinas, CYP2D6/antidepresivos tricĂclicos, CYP2C19/antidepresivos tricĂclicos, NUDT15/tiopurinas, CYP2B6/efavirenz y CYP2C19/clopidogrel. En conclusiĂłn, aunque la contribuciĂłn global de los paĂses de ALC sigue siendo baja en el campo del PGx, se ha observado una mejora relevante en la regiĂłn. La percepciĂłn de la utilidad de las pruebas PGx en la comunidad biomĂŠdica ha cambiado drĂĄsticamente, aumentando la concienciaciĂłn entre los mĂŠdicos, lo que sugiere un futuro prometedor en las aplicaciones clĂnicas de PGx en ALC.Pharmacogenomics (PGx) is considered an emergent field in developing countries. Research on PGx in the Latin American and the Caribbean (LAC) region remains scarce, with limited information in some populations. Thus, extrapolations are complicated, especially in mixed populations. In this paper, we reviewed and analyzed pharmacogenomic knowledge among the LAC scientific and clinical community and examined barriers to clinical application. We performed a search for publications and clinical trials in the field worldwide and evaluated the contribution of LAC. Next, we conducted a regional structured survey that evaluated a list of 14 potential barriers to the clinical implementation of biomarkers based on their importance. In addition, a paired list of 54 genes/drugs was analyzed to determine an association between biomarkers and response to genomic medicine. This survey was compared to a previous survey performed in 2014 to assess progress in the region. The search results indicated that Latin American and Caribbean countries have contributed 3.44% of the total publications and 2.45% of the PGx-related clinical trials worldwide thus far. A total of 106 professionals from 17 countries answered the survey. Six major groups of barriers were identified. Despite the regionâs continuous efforts in the last decade, the primary barrier to PGx implementation in LAC remains the same, the âneed for guidelines, processes, and protocols for the clinical application of pharmacogenetics/pharmacogenomicsâ. Cost-effectiveness issues are considered critical factors in the region. Items related to the reluctance of clinicians are currently less relevant. Based on the survey results, the highest ranked (96%â99%) gene/drug pairs perceived as important were CYP2D6/tamoxifen, CYP3A5/tacrolimus, CYP2D6/opioids, DPYD/fluoropyrimidines, TMPT/thiopurines, CYP2D6/tricyclic antidepressants, CYP2C19/tricyclic antidepressants, NUDT15/thiopurines, CYP2B6/efavirenz, and CYP2C19/clopidogrel. In conclusion, although the global contribution of LAC countries remains low in the PGx field, a relevant improvement has been observed in the region. The perception of the usefulness of PGx tests in biomedical community has drastically changed, raising awareness among physicians, which suggests a promising future in the clinical applications of PGx in LAC
Measurement of the t-channel single top quark production cross section in pp collisions at âs =7 TeV
Peer reviewe
Determinants of enhanced vulnerability to coronavirus disease 2019 in UK patients with cancer: a European study
Despite high contagiousness and rapid spread, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to heterogeneous outcomes across affected nations. Within Europe (EU), the United Kingdom (UK) is the most severely affected country, with a death toll in excess of 100,000 as of January 2021. We aimed to compare the national impact of coronavirus disease 2019 (COVID-19) on the risk of death in UK patients with cancer versus those in continental EU.
Methods: We performed a retrospective analysis of the OnCovid study database, a European registry of patients with cancer consecutively diagnosed with COVID-19 in 27 centres from 27th February to 10th September 2020. We analysed case fatality rates and risk of death at 30 days and 6 months stratified by region of origin (UK versus EU). We compared patient characteristics at baseline including oncological and COVID-19-specific therapy across UK and EU cohorts and evaluated the association of these factors with the risk of adverse outcomes in multivariable Cox regression models.
Findings: Compared with EU (n = 924), UK patients (n = 468) were characterised by higher case fatality rates (40.38% versus 26.5%, p < 0.0001) and higher risk of death at 30 days (hazard ratio [HR], 1.64 [95% confidence interval {CI}, 1.36-1.99]) and 6 months after COVID-19 diagnosis (47.64% versus 33.33%; p < 0.0001; HR, 1.59 [95% CI, 1.33-1.88]). UK patients were more often men, were of older age and have more comorbidities than EU counterparts (p < 0.01). Receipt of anticancer therapy was lower in UK than in EU patients (p < 0.001). Despite equal proportions of complicated COVID-19, rates of intensive care admission and use of mechanical ventilation, UK patients with cancer were less likely to receive anti-COVID-19 therapies including corticosteroids, antivirals and interleukin-6 antagonists (p < 0.0001). Multivariable analyses adjusted for imbalanced prognostic factors confirmed the UK cohort to be characterised by worse risk of death at 30 days and 6 months, independent of the patient's age, gender, tumour stage and status; number of comorbidities; COVID-19 severity and receipt of anticancer and anti-COVID-19 therapy. Rates of permanent cessation of anticancer therapy after COVID-19 were similar in the UK and EU cohorts.
Interpretation: UK patients with cancer have been more severely impacted by the unfolding of the COVID-19 pandemic despite societal risk mitigation factors and rapid deferral of anticancer therapy. The increased frailty of UK patients with cancer highlights high-risk groups that should be prioritised for anti-SARS-CoV-2 vaccination. Continued evaluation of long-term outcomes is warranted
Measurement of the top-quark mass in ttÂŻ events with dilepton final states in pp collisions at âs = 7 TeV
Open Access: This article is distributed under the terms of the Creative Commons Attribution License.-- Chatrchyan, S. et al.The top-quark mass is measured in proton-proton collisions at sâ=7 TeV using a data sample corresponding to an integrated luminosity of 5.0 fbâ1 collected by the CMS experiment at the LHC. The measurement is performed in the dilepton decay channel ttÂŻâ(â+νâb)(ââν¯¯âbÂŻ), where â=e,Îź. Candidate top-quark decays are selected by requiring two leptons, at least two jets, and imbalance in transverse momentum. The mass is reconstructed with an analytical matrix weighting technique using distributions derived from simulated samples. Using a maximum-likelihood fit, the top-quark mass is determined to be 172.5Âą0.4 (stat.)Âą1.5 (syst.) GeV.Acknowledge support from BMWF and FWF (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); MoER, SF0690030s09 and ERDF (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France);BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); MSI (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MON, RosAtom, RAS and RFBR (Russia); MSTD (Serbia); SEIDI and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); ThEP, IPST and NECTEC (Thailand); TUBITAK and TAEK (Turkey); NASU (Ukraine); STFC (United Kingdom); DOE and NSF (USA). Individuals have received support from the Marie-Curie program and the European Research Council (European Union); the Leventis Foundation; the A. P. Sloan Foundation; the Alexander von Humboldt Foundation; the Austrian Science Fund (FWF); the Belgian Federal Science Policy Office; the Fonds pour la Formation Ă la Recherche dans lâIndustrie et dans lâAgriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWTBelgium); the Ministry of Education, Youth and Sports (MEYS) of Czech Republic; the Council of Science and Industrial Research, India; the Compagnia di San Paolo (Torino); and the HOMING PLUS program of Foundation for Polish Science, cofinanced from European Union, Regional Development Fund.Peer Reviewe
Search for standard model production of four top quarks in the lepton + jets channel in pp collisions at âs = 8 TeV
Open Access, Copyright CERN, for the benefit of the CMS Collaboration. Article funded by SCOAP3.Abstract: A search is presented for standard model (SM) production of four top quarks (Formula presented.) in pp collisions in the lepton + jets channel. The data correspond to an integrated luminosity of 19.6 fbâ1 recorded at a centre-of-mass energy of 8 TeV with the CMS detector at the CERN LHC. The expected cross section for SM (Formula presented.) production is (Formula presented.). A combination of kinematic reconstruction and multivariate techniques is used to distinguish between the small signal and large background. The data are consistent with expectations of the SM, and an upper limit of 32 fb is set at a 95% confidence level on the cross section for producing four top quarks in the SM, where a limit of 32 Âą 17 fb is expected
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