349 research outputs found

    Advances in cyclin-dependent kinase inhibitors for the treatment of melanoma

    Get PDF
    Despite the recent advances in the treatment of malignant melanoma with immunotherapy and BRAF/MEK targeted agents, advanced disease still beholds a poor prognosis for a significant proportion of patients. Cyclin dependent kinase (CDK) inhibitors have been investigated as novel melanoma therapeutics throughout a range of phase 1 and 2 trials, as single agents and in combination with established treatments. Areas covered: This article summarises the rationale for, and development of CDK inhibitors in melanoma, with their evolution from pan-CDK inhibitors to highly specific agents, throughout clinical trials and finally their potential future use. Expert opinion: Whilst CDK inhibitors have been practice changing in breast cancer management, their efficacy is yet to be proven in melanoma. Combination with BRAF/MEK inhibitors has been hindered by dose limiting toxicities, but their role may yet to be found within the spectrum of biomarker derived personalised melanoma management. The effect that CDK inhibitors can have as an adjunct to immunotherapy also remains to be seen

    Inner products of resonance solutions in 1-D quantum barriers

    Get PDF
    The properties of a prescription for the inner products of the resonance (Gamow states), scattering (Dirac kets), and bound states for 1-dimensional quantum barriers are worked out. The divergent asypmtotic behaviour of the Gamow states is regularized using a Gaussian convergence factor first introduced by Zel'dovich. With this prescription, most of these states (with discrete complex energies) are found to be orthogonal to each other, to the bound states, and to the Dirac kets, except when they are neighbors, in which case the inner product is divergent. Therefore, as it happens for the continuum scattering states, the norm of the resonant ones remains non-calculable. Thus, they exhibit properties half way between the (continuum real) Dirac-delta orthogonality and the (discrete real) Kronecker-delta orthogonality of the bound states.Comment: 13 pages, 2 figure

    Gauge Fixing in Higher Derivative Gravity

    Get PDF
    Linearized four-derivative gravity with a general gauge fixing term is considered. By a Legendre transform and a suitable diagonalization procedure it is cast into a second-order equivalent form where the nature of the physical degrees of freedom, the gauge ghosts, the Weyl ghosts, and the intriguing "third ghosts", characteristic to higher-derivative theories, is made explicit. The symmetries of the theory and the structure of the compensating Faddeev-Popov ghost sector exhibit non-trivial peculiarities.Comment: 21 pages, LaTe

    Valoración de pacientes tratados con hemodiálisis según la Ley de Promoción de la Autonomía Personal y Atención a las personas en situación de dependencia

    Get PDF
    La valoración del grado de dependencia de los pacientes en diálisis ha sido objeto de interés como indicador clínico y organizativo. El objetivo del estudio es conocer el grado de dependencia que presentan las personas sometidas a tratamiento con diálisis en Catalunya, según los criterios de la Ley sobre Promoción de la Autonomía Personal y Atención a las personas en situación de dependencia. Se ha realizado un estudio descriptivo transversal en 42 centros de Cataluña sobre el grado de dependencia de los pacientes en hemodiálisis. La recogida de datos se hizo mediante una encuesta basada en el baremo de la Ley más datos sociodemográfico y características del tratamiento. De los pacientes que componían la población renal de Cataluña fueron considerados por los profesionales sanitarios con algún grado de dependencia 806, de ellos 425 eran hombres y 381 mujeres; un 61% tienen edades superiores a 70 años. El 53% viven en pareja y el 80,1% tenían uno o más hijos. El 77,4% de los pacientes habían sido trabajadores no cualifi cados, y el 65,4% dijeron no tener estudios. Se consideraron no dependientes 137 pacientes, con dependencia moderada 350, con dependenci

    Comparative Study of Lifestyle: Eating Habits, Sedentary Lifestyle and Anthropometric Development in Spanish 5- To 15-yr-Olds

    Get PDF
    Background: The infant-juvenile period is one of high vulnerability during the lifestyles chosen become determining factors for future health status. This study aimed to evaluate lifestyle, specifically eating habits and physical activity, in 5-15-year-olds in Spain and their health status (anthropometry). Methods: This cross-sectional population study with two time points (2006 and 2013) was conducted by compiling data from the Spanish National Health Survey. We used the minor survey, specifically the data from the Health De-terminants module, which included 5-15-year-olds. Compiled information was obtained from parents or guardians. Results: The overall overweight and obesity prevalence in Spain (2013) in 5- to 15-year-olds is 24.3%. A drop of 8.2% in meat consumption was found, while overall intake was high. Daily intake of plant-based food (fruit, vegetables, pulses) was low, especially vegetables (32.9%). Increased sedentary lifestyle was observed, probably because the use of communication technologies has increased in recent years (P<0.001). Moreover, watching TV rose to 19.3% for 1 hour/day watching TV on weekdays and to 23.5% at weekends. Conclusion: When comparing the two time points (2006 and 2013), we observed that lifestyle, eating habits and phys-ical activity strongly associated with the Spanish infant-juvenile population¿s anthropometry. Mediterranean diet pat-terns seem to be abandoned and physical activity is practiced less, which will have a negative impact on future quality of life

    Non-Linear Affine Embedding of the Dirac Field from the Multiplicity-Free SL(4,R) Unirreps

    Get PDF
    The correspondence between the linear multiplicity-free unirreps of SL(4, R) studied by Ne'eman and {\~{S}}ija{\~{c}}ki and the non-linear realizations of the affine group is worked out. The results obtained clarify the inclusion of spinorial fields in a non-linear affine gauge theory of gravitation.Comment: 13 pages, plain TeX, macros include

    Tunnelling of plane waves through a square barrier

    Full text link
    The time evolution of plane waves in the presence of a 1-dimensional square quantum barrier is considered. Comparison is made between the cases of an infinite and a cut-off (shutter) initial plane wave. The difference is relevant when the results are applied to the analysis of the tunnelling regime. This work is focused on the analytical calculation of the time-evolved solution and highlights the contribution of the resonant (Gamow) states. PACS numbers: 11.10.Ef, 11.10.Lm, 04.60Comment: 16 page

    Ostrogradski Formalism for Higher-Derivative Scalar Field Theories

    Get PDF
    We carry out the extension of the Ostrogradski method to relativistic field theories. Higher-derivative Lagrangians reduce to second differential-order with one explicit independent field for each degree of freedom. We consider a higher-derivative relativistic theory of a scalar field and validate a powerful order-reducing covariant procedure by a rigorous phase-space analysis. The physical and ghost fields appear explicitly. Our results strongly support the formal covariant methods used in higher-derivative gravity.Comment: 22 page

    Light deflection in Weyl gravity: critical distances for photon paths

    Full text link
    The Weyl gravity appears to be a very peculiar theory. The contribution of the Weyl linear parameter to the effective geodesic potential is opposite for massive and nonmassive geodesics. However, photon geodesics do not depend on the unknown conformal factor, unlike massive geodesics. Hence light deflection offers an interesting test of the Weyl theory. In order to investigate light deflection in the setting of Weyl gravity, we first distinguish between a weak field and a strong field approximation. Indeed, the Weyl gravity does not turn off asymptotically and becomes even stronger at larger distances. We then take full advantage of the conformal invariance of the photon effective potential to provide the key radial distances in Weyl gravity. According to those, we analyze the weak and strong field regime for light deflection. We further show some amazing features of the Weyl theory in the strong regime.Comment: 20 pages, 9 figures (see published version for a better resolution, or online version at stacks.iop.org/CQG/21/1897
    corecore