Spectra of ultrabroadband squeezed pulses and the finite-time Unruh-Davies effect

We study spectral properties of quantum radiation of ultimately short duration. In particular, we introduce a continuous multimode squeezing operator for the description of subcycle pulses of entangled photons generated by a coherent-field driving in a thin nonlinear crystal with second order susceptibility. We find the ultrabroadband spectra of the emitted quantum radiation perturbatively in the strength of the driving field. These spectra can be related to the spectra expected in an Unruh-Davies experiment with a finite time of acceleration. In the time domain, we describe the corresponding behavior of the normally ordered electric field variance.Comment: 11 pages, 5 figure

Subcycle squeezing of light from a time flow perspective

Light as a carrier of information and energy plays a fundamental role in both general relativity and quantum physics, linking these areas that are still not fully compliant with each other. Its quantum nature and spatio-temporal structure are exploited in many intriguing applications ranging from novel spectroscopy methods of complex many-body phenomena to quantum information processing and subwavelength lithography. Recent access to subcycle quantum features of electromagnetic radiation promises a new class of time-dependent quantum states of light. Paralleled with the developments in attosecond science, these advances motivate an urgent need for a theoretical framework that treats arbitrary wave packets of quantum light intrinsically in the time domain. Here, we formulate a consistent time domain theory of the generation and sampling of few-cycle and subcycle pulsed squeezed states, allowing for a relativistic interpretation in terms of induced changes in the local flow of time. Our theory enables the use of such states as a resource for novel ultrafast applications in quantum optics and quantum information.Comment: 24 pages, 7 figures (including supplementary information

Pricing of project finance bonds: a comparative analysis of primary market spreads

This paper provides a comparative analysis of project finance (PF) and traditional corporate finance (CF) bond spreads and pricing. Using a cross-section of 47,196 bonds issued worldwide in the 1993–2020 period, we show that PF and CF bonds are differently priced, PF bonds have higher spreads than comparable CF bonds, and although ratings are the most important pricing determinant for PF and CF bonds at issuance, investors rely on other contractual, macroeconomic, and firms' characteristics beyond these ratings. Our results do not support the hypothesis of PF transactions as mechanisms of reducing sponsoring firms' funding costs: the cost of borrowing affects financing choices and PF transactions' weighted average spread is higher than that of comparable CF bond deals. We also find that economies of scale, risk management, and information asymmetry arguments affect sponsoring firms' choice between PF and CF transactions.N/

Regeneração natural de castanheira da Amazônia e interação de seu crescimento inicial com atributos do solo e luz.

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Bovine milk lactoferrin selectively kills highly metastatic prostate cancer PC-3 and osteosarcoma MG-63 cells in vitro

Prostate cancer and osteosarcoma are the second most common type of cancer affecting men and the fifth most common malignancy among adolescents, respectively. The use of non-toxic natural or natural-derived products has been one of the current strategies for cancer therapy, owing to the reduced risks of induced-chemoresistance development and absence of secondary effects. In this perspective, lactoferrin (Lf), a natural protein derived from milk, emerges as a promising anticancer agent due to its well-recognized cytotoxicity and anti-metastatic activity. Here, we aimed to ascertain the potential activity of bovine Lf (bLf) against highly metastatic cancer cells. The bLf effect on prostate PC-3 and osteosarcoma MG-63 cell lines, both displaying plasmalemmal V-ATPase, was studied and compared with the breast cancer MDA-MB-231 and the non-tumorigenic BJ-5ta cell lines. Cell proliferation, cell death, intracellular pH, lysosomal acidification and extracellular acidification rate were evaluated. Results show that bLf inhibits proliferation, induces apoptosis, intracellular acidification and perturbs lysosomal acidification only in highly metastatic cancer cell lines. In contrast, BJ-5ta cells are insensitive to bLf. Overall, our results establish a common mechanism of action of bLf against highly metastatic cancer cells exhibiting plasmalemmal V-ATPase. This study opens promising perspectives for further research on the anticancer role of Lf, which ultimately will contribute to its safer and more rational application in the human therapy of these life-threatening cancers.This study was supported by national funds through Fundação para a Ciência e Tecnologia (FCT) under the scope of the projects: UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569), UID/ BIO/04469/2013 (POCI-01-0145-FEDER-006684), FCT-ANR/ BEX-BCM/0175/2012, PEstOE/BIA/UI4050/2014, RECI/BBBEBI/0179/2012 (FCOMP-01-0124-FEDER-027462), and PTDC/ SAU-BMA/121028/2010.info:eu-repo/semantics/publishedVersio