Nuno Miguel Carvalho Santos

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Exoplanets down to the size of Earth have been found, but not in the habitable zone--that is, at a distance from the parent star at which water, if present, would be liquid. There are planets in the habitable zone of stars cooler than our Sun, but for reasons such as tidal locking and strong stellar activity, they are unlikely to harbour water-carbon life(More)
We report a spectroscopic orbit with period P = 3.52433 ± 0.00027 days for the planetary companion that transits the solar-type star HD 209458. For the metallicity, mass, and radius of the star we derive [Fe/H]= 0.00 ± 0.02, M * = 1.1 ± 0.1 M ⊙ , and R * = 1.3 ± 0.1 R ⊙. This is based on a new analysis of the iron lines in our HIRES template spectrum, and(More)
With the goal of confirming the metallicity " excess " observed in stars with planetary mass companions, we have conducted a high-precision spectroscopic study of a " comparison " sample of dwarfs included in the CORALIE extra-solar planet survey (Santos, Israelian, & Mayor 2001). The targets were chosen following two basic criteria: they make part of a(More)
Antimicrobial peptides (AMPs) are important potential alternatives to conventional therapies against bacterial infections. rBPI(21) is a 21 kDa peptide based on the N-terminal region of the neutrophil bactericidal/permeability-increasing protein (BPI). This AMP possesses highly selective bactericidal effects on Gram-negative bacteria and have affinity for(More)
Over the last years, antimicrobial peptides (AMPs) have been the focus of intense research toward the finding of a viable alternative to current antifungal drugs. Defensins are one of the major families of AMPs and the most represented among all eukaryotic groups, providing an important first line of host defense against pathogenic microorganisms. Several(More)
Over the past two years, the search for low-mass extrasolar planets has led to the detection of seven so-called 'hot Neptunes' or 'super-Earths' around Sun-like stars. These planets have masses 5-20 times larger than the Earth and are mainly found on close-in orbits with periods of 2-15 days. Here we report a system of three Neptune-mass planets with(More)
LJ001 is a lipophilic thiazolidine derivative that inhibits the entry of numerous enveloped viruses at non-cytotoxic concentrations (IC50 ≤ 0.5 µM), and was posited to exploit the physiological difference between static viral membranes and biogenic cellular membranes. We now report on the molecular mechanism that results in LJ001's specific inhibition of(More)
Partition of the intrinsically fluorescent HIV fusion inhibitor enfuvirtide into lipidic membranes is relatively high (Delta G =6.6 kcal x mol(-1)) and modulated by cholesterol. A shallow position in the lipidic matrix makes it readily available for interaction with gp41. No conformational energetic barrier prevents enfuvirtide from being active in both(More)
Enfuvirtide and T-1249 are two HIV-1 fusion inhibitor peptides that bind to gp41 and prevent its fusogenic conformation, inhibiting viral entry into host cells. Previous studies established the relative preferences of these peptides for membrane model systems of defined lipid compositions. We aimed to understand the interaction of these peptides with the(More)
Context. Nine extrasolar planets with masses between 110 and 430M ⊕ are known to transit their star. The knowledge of their masses and radii allows an estimate of their composition, but uncertainties on equations of state, opacities and possible missing energy sources imply that only inaccurate constraints can be derived when considering each planet(More)