Anomalous quartic WWγγWW\gamma\gamma couplings in epep collisions at the LHeC and the FCC-he

We conducted a study on measuring $W^+W^-$ production and on the sensitivity limits at $95\%$ Confidence Level on thirteen anomalous couplings obtained by dimension-8 operators which are related to the anomalous quartic $WW\gamma\gamma$ couplings. We consider the main $e^-p \to e^-\gamma^*\gamma^*p \to e^-W^+W^-p$ reaction with the sub-process $\gamma^*\gamma^* \to W^+W^-$ at the Large Hadron electron Collider (LHeC) and the Future Circular Collider-hadron electron (FCC-he). For the LHeC, energies of the $e^-$ beams are taken to be $E_e =60$ and 140 GeV and the energy of the $p$ beams is taken to be $E_p = 7$ TeV. For the FCC-he, energies of the $e^-$ beams are taken to be $E_e =60$ and 140 GeV and the energy of the $p$ beams is taken to be $E_p = 50$ TeV, respectively. It is interesting to notice that the LHeC and the FCC-he will lead to model-independent limits on the anomalous quartic $WW\gamma\gamma$ couplings which are one order of magnitude stringent than the CMS Collaboration limits, in addition to being competitive with other limits reported in the literature.Comment: 28 pages, 10 Figures and 13 Table

El objeto de estudio de la disciplina de marketing

En este artículo los autores hacen una profunda y exhaustiva revisión de la literatura dedicada a la búsqueda del objeto de la disciplina del marketing. Primero se analiza el concepto de marketing, luego se estudia el intercambio como la base sobre lacual gira toda la actividad de marketing, para posteriormente presentar el intercambio relacional como una de sus más recientes aproximaciones conceptuales.

Bacterias y su implicación en el fallo de implantes de Titanio

Peer Reviewe

Pasatiempos en la vida militar. Juegos y juguetes en el Castillo de San Severino, Matanzas, Cuba

Se examinan las distintas evidencias asociadas a pasatiempos encontradas en excavaciones arqueológicas realizadas en el Castillo de San Severino, en la provincia de Matanzas, Cuba. Se analiza la información histórica referente a las funciones de la dotación de la fortaleza y sus posibles ratos de ocio apuntando a la confección de juegos en el lugar y la utilización de otros insertados en el ámbito militar

Photochemistry of RNA, RNA Monomers, and Plausible Prebiotic Precursors

Sunlight is the primary source of energy to promote change on Earth. In this context, ultraviolet radiation can be thought as a catalyst of chemical change to refine chemical feedstocks and facilitate their transformations into the building blocks of life. To establish reasonable environmental constraints for the chemical origins of life, it is central to understand how the photochemical reactivity or photochemical resistance of prebiotic molecules might have supported the formation of the RNA monomers on the Earth\u27s surface and particularly in aqueous solution. In this chapter, the photochemistry of the RNA monomers and several conceivably important prebiotic precursors are reviewed. The emphasis is on delineating the primary electronic relaxation or photochemical reaction pathways that may have enabled the accumulation and the selection of the RNA monomers as the building blocks of life during prebiotic times. Finally, the moderately investigated photochemistry of RNA is summarized and contrasted to that of DNA. It is surmised that the enhanced structural rigidity and the increased excitation delocalization length in RNA may have conspired during prebiotic times for RNA oligomers to prosper under the otherwise harsh ultraviolet radiation conditions of early Earth

Involvement of Free Radicals in the Development and Progression of Alzheimer’s Disease

Alzheimer’s disease (AD) is a major dementia related to an overproduction of free radicals (FRs), which leads to the generation of oxidative stress in brain tissue. Amyloid beta-peptide of 42 amino acid residues (Aβ1–42) is the main source of FRs in patients with AD. βA1–42 results from hydrolysis of the amyloid precursor protein by β-secretase in a process known as the amyloidogenic pathway. During βA1–42 aggregation, the peptide interacts with various transition metals to produce hydrogen peroxide (H2O2) by the Fenton reaction, generating the hydroxyl radical (•OH), which damages lipids, proteins, and nucleic acids, thereby contributing to neurodegeneration. In addition, βA1–42 is recognized by microglial receptors; it activates these cells, causing overproduction of superoxide anion (O2•−) by NADPH oxidase; O2•− is also converted into H2O2 and finally to •OH in the Fenton reaction. Other factors that contribute to oxidative stress during microglial activation are the overproduction of nitric oxide and interleukins and the overexpression of some enzymes, including cyclooxygenase and inducible nitric oxide synthase, all of which contribute to FR production. Currently, various models in vitro and in vivo exist that permit quantification of O2•− and H2O2 and determination of the effects of these reactive oxygen species

Is the Fluorescence Quantum Yield of Tryptophan Independent of Excitation Wavelength?

Tryptophan is a fluorescent amino acid that is commonly used as a probe in protein structure-dynamics studies. It is also widely used as a convenient standard for measurements of fluorescence quantum yields of organic and bioorganic molecules. Literature values of the fluorescence quantum yield range from 0.13 to 0.15 upon excitation of tryptophan at 270 nm in aqueous solution. Even though the fluorescence quantum yield of tryptophan is known with a high degree of accuracy upon excitation at 270 nm (i.e., ca. ± 0.02), this value is being used indiscriminately in the literature for the determination of the fluorescence quantum yield of molecules at other excitation wavelengths. In those studies, the assumption has been made that the magnitude of the fluorescence quantum yield of tryptophan does not change with excitation wavelength. This assumption is based on the so-called Kasha’s rule, which states that fluorescence emission occurs in appreciable yield only from the lowest excited singlet state of an organic molecule. Consequently, the fluorescence quantum yield is typically independent of the excitation wavelength used. However, many molecules are known to not obey the Kasha’s rule. Therefore, in this study, we examine the hypothesis that the fluorescence quantum yield of tryptophan does not depend on the excitation wavelength used. We also investigate if the fluorescence quantum yield of tryptophan varies when the salt concentration of the phosphate buffer solution at a physiological pH of 7.4 is varied. The results demonstrate that the fluorescence quantum yield of tryptophan depends on excitation wavelength. It is, however, independent of the ionic strength of the buffered solution in a salt concentration range from 5 to 100 millimolar. A photophysical relaxation mechanism that satisfactorily explains the excitation wavelength dependence of the fluorescence quantum yield of tryptophan will be presented.https://commons.case.edu/intersections-fa20/1002/thumbnail.jp

Eficacia del diclofenaco tópico vs. nepafenaco tópico en la reducción del dolor durante la fotocoagulación panretiniana

ResumenPropósitoComparar la eficacia del diclofenaco tópico 0.1% vs. nepafenaco tópico en reducir el dolor asociado a la fotocoagulación panretiniana con láser argón.Material y métodosEnsayo clínico aleatorizado doble enmascarado, 132 pacientes (183 ojos) con diagnóstico de retinopatía diabética proliferativa tratados con fotocoagulación panretiniana. Aleatorización en 2 grupos: diclofenaco y nepafenaco tópicos. Se aplicaron 2 dosis de los analgésicos tópicos previas a la fotocoagulación panretiniana, se evaluó el dolor inmediatamente y 15min después. Se analizó nivel de dolor, efectos adversos y síntomas asociados al finalizar la fotocoagulación retiniana.ResultadosLa mediana de la edad para ambos grupos fue de 55 años, relación H:M de 1:1.4. El nivel de dolor inmediato fue de 35.5 (RIC 14-72) para el nepafenaco y de 45 (RIC 14-70) para el diclofenaco (p=0.48). A los 15min fue de 30 (RIC 4-50) para el nepafenaco y de 20 (RIC 2-50) para el diclofenaco (p=0.48). No hubo diferencias significativas en síntomas asociados entre los grupos ni efectos adversos en la superficie ocular.ConclusionesEl tratamiento previo con nepafenaco y diclofenaco tópicos es igualmente eficaz y seguro para reducir el dolor asociado a la fotocoagulación panretiniana en pacientes con retinopatía diabética proliferativa.AbstractPurposeTo compare the efficacy of topical diclofenac 0.1% vs topical nepafenac in reducing pain associated to argon laser retinal photocoagulationMaterial and methodsDouble blinded, randomized clinical trial. One hundred thirty two patients with diagnosis of proliferative diabetic retinopathy treated with retinal photocoagulation. Randomization in to 2 groups: topical diclofenac and nepafenac. Before retinal photocoagulation 2 doses of topical non-steroidal anti-inflammatory drugs were applied, pain was assessed immediately and 15minutes after. Level of pain, adverse effects and associated symptoms at the end of retinal photocoagulation were analyzed.ResultsThe median for age in both groups was 55 years, M:F ratio of 1:1.4. The immediate level of pain was 35.5 (ICR 14-72) for nepafenac and 45 (ICR 14-70) for diclofenac (P=.48). At 15minutes the pain level was 30 (ICR 4-50) for nepafenac and 20 (ICR 2-50) for diclofenac. There was no difference in associated symptoms or adverse effects among groups.ConclusionsThe preventive treatment with topical nepafenac and diclofenac is equally effective and safe for reducing the pain associated with retinal photocoagulation in patients with proliferative diabetic retinopathy