251 research outputs found

    Synthesis of Graphene Nanoribbons on a Kinked Au Surface: Revealing the Frontier Valence Band at the Brillouin Zone Center

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    Graphene nanoribbons (GNRs) can be synthesized with atomic precision through on-surface chemistry of self-assembled organic precursors on metal surfaces. Here, we examine the growth of seven-armchair GNRs (7-AGNRs) on the Au(16 14 15) vicinal surface, namely, a surface vicinal to Au(111) that features kinked steps. During the thermal activation of the polymerization and cyclodehydrogenation processes that produce the GNRs, the kinked substrate undergoes a strong step-edge reshaping, accompanied by a massive missing-row reconstruction within (111) terraces that aligns GNRs preferentially along two equivalent [11¯ 0] directions. Using angle-resolved photoemission, we are able to detect the occupied frontier band of the 7-AGNR at the center of the first Brillouin zone, as predicted by theoretical calculations. This allows to unambiguously determine the relevant 7-AGNR band properties, namely, energy and effective mass. Copyrigh

    Caracterização e ocorrência do distúrbio do amolecimento precoce em mamões 'Golden'

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    The occurrence of green skin and soft pulp in 'Golden' papaya fruit during certain seasons has been reported by farmers in the northern of the state of Espirito Santo, Brazil. The objective of this study was to characterize and determine the occurrence of this disorder, which was referred as "early softening disorder". Fruits were harvested weekly for 11 months (from September to July). The fruits were stored at 10°C, and then fruit flesh firmness and skin color were analyzed. The results of the firmness test were submitted to regression analysis assuming a linear trendline. The slope of the curve was called the 'softening index' (SI). Fruits with early softening are characterized by a loss of firmness in less than 10 days, even when stored under refrigeration. Although softened, the skin of the fruit remains partially green. Fruits with the disorder occurred more frequently from mid-summer to mid-autumn (February to May). It is not possible to distinguish early softening disorder fruits from those without the disorder by skin color and flesh firmness analysis at the time of the harvest.Tem sido relatado por produtores da região norte do Espírito Santo a ocorrência de mamões 'Golden' com casca verde e polpa mole, em determinadas épocas do ano. O objetivo deste trabalho foi caracterizar e determinar a ocorrência deste distúrbio denominado de amolecimento precoce. Foram realizadas coletas semanais durante 11 meses (período de setembro a julho). Os frutos foram armazenados a 10°C e analisados quanto à firmeza da polpa e à cor da casca. Os resultados de firmeza da polpa foram submetidos à análise de regressão, assumindo-se que a equação é do tipo linear, e o ângulo de inclinação da curva foi chamado Índice de Amolecimento (IA). Frutos com o distúrbio caracterizaram-se pela perda da firmeza em menos de 10 dias, mesmo quando armazenados sob refrigeração. Embora amolecidos, a coloração da casca manteve-se parcialmente verde. A maior frequência de frutos com o distúrbio ocorreu de meados de verão a meados de outono (fevereiro a maio). Não é possível distinguir frutos com o distúrbio do amolecimento precoce daqueles normais pela análise da cor da casca e da firmeza da polpa, no momento da colheita

    Анализ финансовой среды стоматологической организации

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    The Main by purpose given article is a study of the financial analysis, estimation and identification of the internal problems to organizations for preparing, motivations and taking the different management decisions, including in the field of developments, output from crisis, transition to procedure bankruptcy, buying-selling the business or block of shares, attraction investment. Given our studies have allowed to value the results to financial activity stomatology polyclinics and analyses the financial facility on the source of the shaping and grade of membership.Представлены результаты изучения финансового анализа, оценки и идентификации внутренних проблем организации для подготовки, обоснования и принятия различных управленческих решений, в том числе в области развития, выхода из кризиса, перехода к процедурам банкротства, покупки-продажи бизнеса или пакета акций, привлечения инвестиций (заемных средств). Данные наших исследований позволили оценить результаты финансовой деятельности стоматологической поликлиники и проанализировать финансовые ресурсы по источникам формирования и степени принадлежности

    The thrombolytic and cytotoxic effects of nigella sativa (L.) seeds: the prophetic medicine

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    The Water-Soluble Extract (WSE) is a crude bioactive phytoconstituent of Nigella sativa (L.) seeds discovered recently. The current findings report about the thrombolytic and cytotoxic effects of WSE using human blood clot lysis and brine shrimp lethality (BSL) bioassay. The thrombolytic effect of WSE (1,666.67 µg/mL) was determined via the clot and lysate weight measurements compared to streptokinase (STK) of 30,000 IU/mL and normal saline (NS) while the cytotoxicity of WSE (44.14-2,000 µg/mL) against vincristine sulfate (VCS;3.125-100 µg/mL). WSE has shown extremely statistically significant (p<0.0001) clot lysis (90.00%) compared to NS (3.76%) whilst it was also significantly different (p<0.0063) to STK (72.41%) exhibiting LC50 of 1,795.90 µg/mL vs. VCS (39.25 µg/mL) in a dose-dependent manner. The current results suggested WSE has a potent thrombolytic effect with mild dose-dependent cytotoxicity towards brine shrimp nauplii (Artemia salina). It also suggested WSE might have enzymatic roles on thrombin, fibrin, and plasmin of blood. This pharmacological action of WSE is might be due to its antioxidant property, short-chain fatty acids and/or amino acids. Further studies are highly recommended on the enzymatic role(s) and bioactive phytoconstituents of WSE

    Studies of Hadronic Event Structure in e+e- Annihilation from 30 GeV to 209 GeV with the L3 Detector

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    In this Report, QCD results obtained from a study of hadronic event structure in high energy e^+e^- interactions with the L3 detector are presented. The operation of the LEP collider at many different collision energies from 91 GeV to 209 GeV offers a unique opportunity to test QCD by measuring the energy dependence of different observables. The main results concern the measurement of the strong coupling constant, \alpha_s, from hadronic event shapes and the study of effects of soft gluon coherence through charged particle multiplicity and momentum distributions.Comment: To appear in Physics Report

    Measurement of the View the tt production cross-section using eμ events with b-tagged jets in pp collisions at √s = 13 TeV with the ATLAS detector

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    This paper describes a measurement of the inclusive top quark pair production cross-section (σtt¯) with a data sample of 3.2 fb−1 of proton–proton collisions at a centre-of-mass energy of √s = 13 TeV, collected in 2015 by the ATLAS detector at the LHC. This measurement uses events with an opposite-charge electron–muon pair in the final state. Jets containing b-quarks are tagged using an algorithm based on track impact parameters and reconstructed secondary vertices. The numbers of events with exactly one and exactly two b-tagged jets are counted and used to determine simultaneously σtt¯ and the efficiency to reconstruct and b-tag a jet from a top quark decay, thereby minimising the associated systematic uncertainties. The cross-section is measured to be: σtt¯ = 818 ± 8 (stat) ± 27 (syst) ± 19 (lumi) ± 12 (beam) pb, where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, the integrated luminosity and the LHC beam energy, giving a total relative uncertainty of 4.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. A fiducial measurement corresponding to the experimental acceptance of the leptons is also presented

    Search for TeV-scale gravity signatures in high-mass final states with leptons and jets with the ATLAS detector at sqrt [ s ] = 13TeV

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    A search for physics beyond the Standard Model, in final states with at least one high transverse momentum charged lepton (electron or muon) and two additional high transverse momentum leptons or jets, is performed using 3.2 fb−1 of proton–proton collision data recorded by the ATLAS detector at the Large Hadron Collider in 2015 at √s = 13 TeV. The upper end of the distribution of the scalar sum of the transverse momenta of leptons and jets is sensitive to the production of high-mass objects. No excess of events beyond Standard Model predictions is observed. Exclusion limits are set for models of microscopic black holes with two to six extra dimensions

    Search for dark matter produced in association with a hadronically decaying vector boson in pp collisions at sqrt (s) = 13 TeV with the ATLAS detector

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    A search is presented for dark matter produced in association with a hadronically decaying W or Z boson using 3.2 fb−1 of pp collisions at View the MathML sources=13 TeV recorded by the ATLAS detector at the Large Hadron Collider. Events with a hadronic jet compatible with a W or Z boson and with large missing transverse momentum are analysed. The data are consistent with the Standard Model predictions and are interpreted in terms of both an effective field theory and a simplified model containing dark matter
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