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1.
Curr Oncol Rep ; 22(6): 62, 2020 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32495112

RESUMO

PURPOSE OF REVIEW: Clinical evidence suggesting the beneficial effects of vitamin D on survival of patients with cancer has been accumulating. Recent articles were thoroughly reviewed to determine if there is enough evidence to conclude that vitamin D supplementation improves survival of patients with cancer. RECENT FINDINGS: Meta-analyses of observational studies showed that higher blood 25-hydroxyvitamin D levels in patients with cancer at a variety of sites were associated with lower cancer-specific and overall mortalities. Moreover, meta-analyses of randomized clinical trials (RCTs) also suggested that vitamin D supplementation improved the survival of patients with cancer. However, each RCT used in these meta-analyses, as well as very recent RCTs, e.g., the SUNSHINE and the AMATERASU trial, did not show statistical significance in the primary results. For now, compelling evidence that vitamin D supplementation effectively improves survival of patients with cancer is lacking. Thus, confirmatory RCTs are still obligatory for the future.


Assuntos
Neoplasias/mortalidade , Vitamina D/administração & dosagem , Suplementos Nutricionais , Humanos , Neoplasias/sangue , Ensaios Clínicos Controlados Aleatórios como Assunto , Vitamina D/análogos & derivados , Vitamina D/sangue
2.
Nat Commun ; 5: 5080, 2014 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-25270525

RESUMO

In 1913, Maurice de Broglie discovered the presence of X-ray absorption bands of silver and bromine in photographic emulsion. Over the following century, X-ray absorption spectroscopy was established as a standard basis for element analysis, and further applied to advanced investigation of the structures and electronic states of complex materials. Here we show the first observation of an X-ray-induced change of absorption spectra of the iron K-edge for 7.1-keV ultra-brilliant X-ray free-electron laser pulses with an extreme intensity of 10(20) W cm(-2). The highly excited state yields a shift of the absorption edge and an increase of transparency by a factor of 10 with an improvement of the phase front of the transmitted X-rays. This finding, the saturable absorption of hard X-rays, opens a promising path for future innovations of X-ray science by enabling novel attosecond active optics, such as lasing and dynamical spatiotemporal control of X-rays.

3.
J Phys Condens Matter ; 19(7): 072102, 2007 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-22251578

RESUMO

The equation of state for expanded fluid mercury based on the variational associating fluid theory is developed to elucidate the mechanisms of the gas-liquid transition in terms of microscopic interatomic interaction. The theory describes the interaction of an atom with its neighbouring atoms through an effective many-body potential, which is constructed through quantum-chemical calculations of cohesive energies for selected geometries of clusters and bulk crystals. The overall feature of the observed gas-liquid coexistence curve is reproduced accurately without introducing phenomenological adjustable parameters. It is shown that the local aggregation of atoms produces a strong cohesive force due to a change in the local electronic states, which plays a crucial role in the gas-liquid transition. The predicted phase behaviour is consistent with the picture of inhomogeneous expansion, in which the average coordination number is nearly proportional to the average density along the coexistence curve.

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