789 research outputs found

    Quantum Noise Limits for Nonlinear, Phase-Invariant Amplifiers

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    Any quantum device that amplifies coherent states of a field while preserving their phase generates noise. A nonlinear, phase-invariant amplifier may generate less noise, over a range of input field strengths, than any linear amplifier with the same amplification. We present explicit examples of such nonlinear amplifiers, and derive lower bounds on the noise generated by a nonlinear, phase-invariant quantum amplifier.Comment: RevTeX, 6 pages + 4 figures (included in file; hard copy sent on request

    LP 133-373: A New Chromospherically Active Eclipsing dMe Binary with a Distant, Cool White Dwarf Companion

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    We report the discovery of the partially eclipsing binary LP 133-373. Nearly identical eclipses along with observed photometric colors and spectroscopy indicate that it is a pair of chromospherically active dM4 stars in a circular 1.6 day orbit. Light and velocity curve modeling to our differential photometry and velocity data show that each star has a mass and radius of 0.340+/-0.014 Msolar and 0.33+/-0.02 Rsolar. The binary is itself part of a common proper motion pair with LP 133-374, a cool DC or possible DA white dwarf with a mass of 0.49-0.82 Msolar, which would make the system at least 3 Gyr ol

    Discovery of new molecular entities able to strongly interfere with Hsp90 C-terminal domain

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    Heat shock protein 90 (Hsp90) is an ATP dependent molecular chaperone deeply involved in the complex network of cellular signaling governing some key functions, such as cell proliferation and survival, invasion and angiogenesis. Over the past years the N-terminal protein domain has been fully investigated as attractive strategy against cancer, but despite the many efforts lavished in the field, none of the N-terminal binders (termed “classical inhibitors”), currently in clinical trials, have yet successfully reached the market, because of the detrimental heat shock response (HSR) that showed to induce; thus, recently, the selective inhibition of Hsp90 C-terminal domain has powerfully emerged as a more promising alternative strategy for anti-cancer therapy, not eliciting this cell rescue cascade. However, the structural complexity of the target protein and, mostly, the lack of a co-crystal structure of C-terminal domain-ligand, essential to drive the identification of new hits, represent the largest hurdles in the development of new selective C-terminal inhibitors. Continuing our investigations on the identification of new anticancer drug candidates, by using an orthogonal screening approach, here we describe two new potent C-terminal inhibitors able to induce cancer cell death and a considerable downregulation of Hsp90 client oncoproteins, without triggering the undesired heat shock response

    Hyaluronan-carnosine conjugates inhibit Aβ aggregation and toxicity

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    Alzheimer’s disease is the most common neurodegenerative disorder. Finding a pharmacological approach that cures and/or prevents the onset of this devastating disease represents an important challenge for researchers. According to the amyloid cascade hypothesis, increases in extracellular amyloid-β (Aβ) levels give rise to different aggregated species, such as protofibrils, fibrils and oligomers, with oligomers being the more toxic species for cells. Many efforts have recently been focused on multi-target ligands to address the multiple events that occur concurrently with toxic aggregation at the onset of the disease. Moreover, investigating the effect of endogenous compounds or a combination thereof is a promising approach to prevent the side effects of entirely synthetic drugs. In this work, we report the synthesis, structural characterization and Aβ antiaggregant ability of new derivatives of hyaluronic acid (Hy, 200 and 700 kDa) functionalized with carnosine (Car), a multi-functional natural dipeptide. The bioactive substances (HyCar) inhibit the formation of amyloid-type aggregates of Aβ42 more than the parent compounds; this effect is proportional to Car loading. Furthermore, the HyCar derivatives are able to dissolve the amyloid fibrils and to reduce Aβ-induced toxicity in vitro. The enzymatic degradation of Aβ is also affected by the interaction with HyCar

    Colourants on the wall paintings of a mediÓ•val fortress at the mount Sofeh in Isfahan, central Iran

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    Colourants on the twelfth century wall paintings excavated at the fortress located on the mount Sofeh in Isfahan, central Iran, were analysed using micro X-ray fluorescence (µ-XRF), micro Raman spectroscopy (µ-Raman) and high-performance liquid chromatography coupled to electrospray ionization quadropole time-of-flight (HPLC-ESI-Q-TOF). The results of the analyses showed that gypsum, atacamite, carbon black, orpiment and ultramarine blue were used as white, green, black, yellow and blue pigments, respectively. Moreover, three red colourants including red lead, red vermilion and madder red were identified in the wall paintings. Furthermore, possible sources for the colourants are discussed

    Good for the heart, good for the Earth: proposal of a dietary pattern able to optimize cardiovascular disease prevention and mitigate climate change

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    Background and aims: Human and planetary health are inextricably interconnected through food systems. Food choices account for 50% of all deaths for cardiovascular diseases (CVD) - the leading cause of death in Europe - and food systems generate up to 37% of total greenhouse gas (GHG) emissions. Methods and results: Based on a systematic revision of meta-analyses of prospective studies exploring the association between individual foods/food groups and the incidence of CVD, we identified a dietary pattern able to optimize CVD prevention.. This dietary pattern was compared to the current diet of the European population. The nutritional adequacy of both diets was evaluated according to the European Food Safety Authority (EFSA) recommended nutrient intake for the adult population, and their environmental impact was evaluated in terms of carbon footprint (CF). As compared to the current diet, the desirable diet includes higher intakes of fruit, vegetables, wholegrains, low glycemic index (GI) cereals, nuts, legumes and fish, and lower amounts of beef, butter, high GI cereals or potatoes and sugar. The diet here identified provides appropriate intakes of all nutrients and matches better than the current Europeans' one the EFSA requirements. Furthermore, the CF of the proposed diet is 48.6% lower than that of the current Europeans' diet. Conclusion: The transition toward a dietary pattern designed to optimize CVD prevention would improve the nutritional profile of the habitual diet in Europe and, at the same time, contribute to mitigate climate change by reducing the GHG emissions linked to food consumption almost by half

    Coherent States for Particle Beams in the Thermal Wave Model

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    In this paper, by using an analogy among {\it quantum mechanics}, {\it electromagnetic beam optics in optical fibers}, and {\it charge particle beam dynamics}, we introduce the concept of {\it coherent states} for charged particle beams in the framework of the {\it Thermal Wave Model} (TWM). We give a physical meaning of the Gaussian-like coherent structures of charged particle distribution that are both naturally and artificially produced in an accelerating machine in terms of the concept of coherent states widely used in quantum mechanics and in quantum optics. According to TWM, this can be done by using a Schr\"{o}dinger-like equation for a complex function, the so-called {\it beam wave function} (BWF), whose squared modulus is proportional to the transverse beam density profile, where Planck's constant and the time are replaced by the transverse beam emittance and by the propagation coordinate, respectively. The evolution of the particle beam, whose initial BWF is assumed to be the simplest coherent state (ground-like state) associated with the beam, in an infinite 1-D quadrupole-like device with small sextupole and octupole aberrations, is analytically and numerically investigated.Comment: 21 pages, Late

    Correction: Identification of the key structural elements of a dihydropyrimidinone core driving toward more potent Hsp90 C-terminal inhibitors

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    Correction for 'Identification of the key structural elements of a dihydropyrimidinone core driving toward more potent Hsp90 C-terminal inhibitors' by S. Teracciano et al., Chem. Commun., 2016, 52, 12857–12860

    Body mass index in HER2-negative metastatic breast cancer treated with first-line paclitaxel and bevacizumab

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    The evidence emerged from the TOURANDOT trial encourages evaluating the role of anthropometric determinants on treatment outcomes in HER2-negative metastatic breast cancer patients treated with bevacizumab-including regimens. We thus analyzed data from a subgroup of these patients from a larger cohort previously assessed for treatment outcomes. Patients were included in the present analysis if body mass index values had been recorded at baseline. Clinical benefit rates, progression free survival and overall survival were assessed for the overall study population and subgroups defined upon molecular subtype. One hundred ninety six patients were included (N:196). Body mass index showed no impact on clinical benefit rates in the overall study sample and in the luminal cancer subset (p = 0.12 and p = 0.79, respectively), but did so in the triple negative subgroup, with higher rates in patients with body mass index ≥25 (p = 0.03). In the overall study sample, body mass index did no impact progression free or overall survival (p = 0.33 and p = 0.67, respectively). Conversely, in triple negative patients, progression free survival was significantly longer with body mass index ≥25 (6 vs 14 months, p = 0.04). In this subset, overall survival was more favorable (25 vs 19 months, p = 0.02). The impact of the molecular subtype was confirmed in multivariate models including the length of progression free survival, and number of metastatic sites (p < 0.0001). Further studies are warranted to confirm our findings in more adequately sized, ad hoc, prospective studies
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