10,101 research outputs found

    Current medical treatment of estrogen receptor-positive breast cancer

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    Approximately 80% of breast cancers (BC) are estrogen receptor (ER)-positive and thus endocrine therapy (ET) should be considered complementary to surgery in the majority of patients. The advantages of oophorectomy, adrenalectomy and hypophysectomy in women with advanced BC have been demonstrated many years ago, and currently ET consist of (i) ovarian function suppression (OFS), usually obtained using gonadotropin-releasing hormone agonists (GnRHa), (ii) selective estrogen receptor modulators or down-regulators (SERMs or SERDs), (iii) aromatase inhibitors (AIs), or a combination of two or more drugs. For patients aged less than 50 years and ER+ BC, there is no conclusive evidence that the combination of OFS and SERMs (i.e. tamoxifen) or chemotherapy is superior to OFS alone. Tamoxifen users exhibit a reduced risk of BC, both invasive and in situ, especially during the first 5 years of therapy, and extending the treatment to 10 years further reduced the risk of recurrences. SERDs (i.e. fulvestrant) are especially useful in the neoadjuvant treatment of advanced BC, alone or in combination with either cytotoxic agents or AIs. There are two types of AIs: type I are permanent steroidal inhibitors of aromatase, while type II are reversible nonsteroidal inhibitors. Several studies demonstrated the superiority of the third-generation AIs (i.e. anastrozole and letrozole) compared with tamoxifen, and adjuvant therapy with AIs reduces the recurrence risk especially in patients with advanced BC. Unfortunately, some cancers are or became ET-resistant, and thus other drugs have been suggested in combination with SERMs or AIs, including cyclin-dependent kinase 4/6 inhibitors (palbociclib) and mammalian target of rapamycin (mTOR) inhibitors, such as everolimus. Further studies are required to confirm their real usefulness

    Human capital, culture and the onset of the demographic transition

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    This paper uses estimates of the dates at which different countries have experienced their demographic transitions to examine the main historical determinants of these transitions. We first show that genetic distance to the United Kingdom, a measure of cultural relatedness used in Spolaore and Wacziarg (2009), is positively associated with the onset of the demographic transition, implying that countries that have a larger genetic distance from the UK tend to experience later transitions. We then unveil a plausible mechanism that can rationalize this result. We show that genetic distance to the UK is negatively related to a country's initial human capital, measured as its schooling level in 1870. One interpretation of this finding is that a larger genetic distance is associated with higher barriers to technological diffusion and hence a lower demand for human capital. This low demand for human capital then delays the demographic transition by providing less incentives for households to switch from quantity to quality of children. Instrumenting initial human capital using genetic distance to the UK and alternative measures of adherence to Protestantism, we confirm the causal link between human capital and the onset of the demographic transition. Further, we show that the impact of cultural relatedness to the UK can be mainly attributed to its effect on educational levels

    Analytical computation of the off-axis Effective Area of grazing incidence X-ray mirrors

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    Focusing mirrors for X-ray telescopes in grazing incidence, introduced in the 70s, are characterized in terms of their performance by their imaging quality and effective area, which in turn determines their sensitivity. Even though the on-axis effective area is assumed in general to characterize the collecting power of an X-ray optic, the telescope capability of imaging extended X-ray sources is also determined by the variation in its effective area with the off-axis angle. [...] The complex task of designing optics for future X-ray telescopes entails detailed computations of both imaging quality and effective area on- and off-axis. Because of their apparent complexity, both aspects have been, so far, treated by using ray-tracing routines aimed at simulating the interaction of X-ray photons with the reflecting surfaces of a given focusing system. Although this approach has been widely exploited and proven to be effective, it would also be attractive to regard the same problem from an analytical viewpoint, to assess an optical design of an X-ray optical module with a simpler calculation than a ray-tracing routine. [...] We have developed useful analytical formulae for the off-axis effective area of a double-reflection mirror in the double cone approximation, requiring only an integration and the standard routines to calculate the X-ray coating reflectivity for a given incidence angle. [...] Algebraic expressions are provided for the mirror geometric area, as a function of the off-axis angle. Finally, the results of the analytical computations presented here are validated by comparison with the corresponding predictions of a ray-tracing code.Comment: 12 pages, 11 figures, accepted for publication in "Astronomy & Astrophysics", section "Instruments, observational techniques, and data processing". Updated version after grammatical revision and typos correctio

    Longitudinal spin Seebeck coefficient: heat flux vs. temperature difference method

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    The determination of the longitudinal spin Seebeck effect (LSSE) coefficient is currently plagued by a large uncertainty due to the poor reproducibility of the experimental conditions used in its measurement. In this work we present a detailed analysis of two different methods used for the determination of the LSSE coefficient. We have performed LSSE experiments in different laboratories, by using different setups and employing both the temperature difference method and the heat flux method. We found that the lack of reproducibility can be mainly attributed to the thermal contact resistance between the sample and the thermal baths which generate the temperature gradient. Due to the variation of the thermal resistance, we found that the scaling of the LSSE voltage to the heat flux through the sample rather than to the temperature difference across the sample greatly reduces the uncertainty. The characteristics of a single YIG/Pt LSSE device obtained with two different setups was (1.143±0.007)107(1.143\pm0.007)\cdot 10^{-7} Vm/W and (1.101±0.015)107(1.101\pm0.015)\cdot 10^{-7} Vm/W with the heat flux method and (2.313±0.017)107(2.313\pm0.017)\cdot 10^{-7} V/K and (4.956±0.005)107(4.956\pm0.005)\cdot 10^{-7} V/K with the temperature difference method. This shows that systematic errors can be considerably reduced with the heat flux method.Comment: PDFLaTeX, 10 pages, 6 figure

    TBA-like equations and Casimir effect in (non-)perturbative AdS/CFT

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    We consider high spin, ss, long twist, LL, planar operators (asymptotic Bethe Ansatz) of strong N=4{\cal N}=4 SYM. Precisely, we compute the minimal anomalous dimensions for large 't Hooft coupling λ\lambda to the lowest order of the (string) scaling variable L/(lnSλ)\ell \sim L/ (\ln \mathcal{S} \sqrt{\lambda}) with GKP string size lnS2ln(s/λ)\sim\ln \mathcal{S}\equiv 2 \ln (s/\sqrt{\lambda}). At the leading order (lnS)2(\ln \mathcal{S}) \cdot \ell ^2 , we can confirm the O(6) non-linear sigma model description for this bulk term, without boundary term (lnS)0(\ln \mathcal{S})^0. Going further, we derive, extending the O(6) regime, the exact effect of the size finiteness. In particular, we compute, at all loops, the first Casimir correction 0/lnS\ell ^0/\ln \mathcal{S} (in terms of the infinite size O(6) NLSM), which reveals only one massless mode (out of five), as predictable once the O(6) description has been extended. Consequently, upon comparing with string theory expansion, at one loop our findings agree for large twist, while reveal for negligible twist, already at this order, the appearance of wrapping. At two loops, as well as for next loops and orders, we can produce predictions, which may guide future string computations.Comment: Version 2 with: new exact expression for the Casimir energy derived (beyond the first two loops of the previous version); UV theory formulated and analysed extensively in the Appendix C; origin of the O(6) NLSM scattering clarified; typos correct and references adde

    Scanning electron microscopy of the oral apparatus and buccopharyngeal cavity of Atelognathus salai larvae (Anura, Neobatrachia)

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    The aim of this study is to describe the horny structures of the buccal apparatus and buccopharyngeal cavity of A. salai by means ofscanning electron microscopy (SEM), and to compare them to those of the other known species of Atelognathus and related genera

    Entanglement swapping with photons generated on-demand by a quantum dot

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    Photonic entanglement swapping, the procedure of entangling photons without any direct interaction, is a fundamental test of quantum mechanics and an essential resource to the realization of quantum networks. Probabilistic sources of non-classical light can be used for entanglement swapping, but quantum communication technologies with device-independent functionalities demand for push-button operation that, in principle, can be implemented using single quantum emitters. This, however, turned out to be an extraordinary challenge due to the stringent requirements on the efficiency and purity of generation of entangled states. Here we tackle this challenge and show that pairs of polarization-entangled photons generated on-demand by a GaAs quantum dot can be used to successfully demonstrate all-photonic entanglement swapping. Moreover, we develop a theoretical model that provides quantitative insight on the critical figures of merit for the performance of the swapping procedure. This work shows that solid-state quantum emitters are mature for quantum networking and indicates a path for scaling up.Comment: The first four authors contributed equally to this work. 17 pages, 3 figure

    Pancreatic cancer-associated diabetes mellitus: an open field for proteomic applications.

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    Background: Diabetes mellitus is associated with pancreatic cancer in more than 80% of the cases. Clinical, epidemiological, and experimental data indicate that pancreatic cancer causes diabetes mellitus by releasing soluble mediators which interfere with both beta-cell function and liver and muscle glucose metabolism. Methods: We analysed, by matrix-assisted laser desorption ionization time of flight (MALDI-TOF), a series of pancreatic cancer cell lines conditioned media, pancreatic cancer patients' peripheral and portal sera, comparing them with controls and chronic pancreatitis patients' sera. Results: MALDI-TOF analysis of pancreatic cancer cells conditioned media and patients' sera indicated a low molecular weight peptide to be the putative pancreatic cancer-associated diabetogenic factor. The sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of tumor samples from diabetic and non-diabetic patients revealed the presence of a 1500 Da peptide only in diabetic patients. The amino acid sequence of this peptide corresponded to the N-terminal of an S-100 calcium binding protein, which was therefore suggested to be the pancreatic cancer-associated diabetogenic factor. Conclusions: We identified a tumor-derived peptide of 14 amino acids sharing a 100% homology with an S-100 calcium binding protein, which is probably the pancreatic cancer-associated diabetogenic facto

    Influence of Particle Size on Reduction Kinetics of Natural Lateritic Iron Ores

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    This work is to report a laboratory investigation on the influence of particle sizes on reduction behavior of natural lateritic iron ore with anthracite coal under isothermal condition. Themain minerals content of investigated ore were goethite = 62.8%, hematite = 18.3% and magnetite (Fe3O4) = 6.2% and other oxide minerals like alumina = 6.6%, silica = 4.5%, chromate = 3.3% and others. The ore and anthracite coal of -100, -200 and -500 µm size with mol ratio between iron oxide and carbon in the anthracite of 1 : 1.88 were mixed, pressed into a composite of 12 mm diameter and 20 mm long and heated isothermally at four different temperatures for various reduction times. The metallization is determined by the reduction temperature and time. Mostly, effective reduction temperatures were found to be 1100 oC resulted in the highest value of metallization of almost 96 %. The particle size seems has no significant influence on the metallization value at this reduction temperature. However, particle sizes influenced significantly the metallization for reduction temperatures of less than 1100 oC from which values of metallization increased with decreasing in particle sizes

    Precision tools and models to narrow in on the 750 GeV diphoton resonance

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    The hints for a new resonance at 750 GeV from ATLAS and CMS have triggered a significant amount of attention. Since the simplest extensions of the standard model cannot accommodate the observation, many alternatives have been considered to explain the excess. Here we focus on several proposed renormalisable weakly-coupled models and revisit results given in the literature. We point out that physically important subtleties are often missed or neglected. To facilitate the study of the excess we have created a collection of 40 model files, selected from recent literature, for the Mathematica package SARAH. With SARAH one can generate files to perform numerical studies using the tailor-made spectrum generators FlexibleSUSY and SPheno. These have been extended to automatically include crucial higher order corrections to the diphoton and digluon decay rates for both CP-even and CP-odd scalars. Additionally, we have extended the UFO and CalcHep interfaces of SARAH, to pass the precise information about the effective vertices from the spectrum generator to a Monte-Carlo tool. Finally, as an example to demonstrate the power of the entire setup, we present a new supersymmetric model that accommodates the diphoton excess, explicitly demonstrating how a large width can be obtained. We explicitly show several steps in detail to elucidate the use of these public tools in the precision study of this model.Comment: 184 pages, 24 figures; model files available at http://sarah.hepforge.org/Diphoton_Models.tar.gz; v2: added a few clarifications and reference
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