Rozdíly mezi pravdivou a lživou online textovou komunikací

V článku porovnáváme „běžnou“ a „lživou“ internetovou komunikaci vedenou přes Windows Live Messenger. Respondenti měli v experimentálně pojatém výzkumu nejprve za úkol komunikovat s druhou neznámou osobou, poté dostali za úkol komunikovat s jinou osobou a přitom předstírat identitu opačného pohlaví a lhát. Následně jsme porovnávali jazykové prostředky, které byly v obou typech komunikace používány. Výsledky ukázaly, že lživá komunikace obsahovala větší počet slovesných tvarů v prvním stupni, více příslovcí, vět a otázek a menší počet číslovek a slov v druhém pádě a jejich vzkazy byly kratší. Rozdíly mezi klamavou a běžnou komunikací se lišily u mužů a žen: u mužů se při klamavé komunikaci oproti pravdivé změnily spíše lingvistické charakteristiky jejich projevu (počet příslovcí), kdežto u žen spíše charakteristiky strategie komunikace (počet otázek). Článek může sloužit jako výchozí bod pro práci na nástrojích umožňujících automatickou analýzu klamání na internetu v českém jazyce

Stability of a Giant Connected Component in a Complex Network

We analyze the stability of the network's giant connected component under impact of adverse events, which we model through the link percolation. Specifically, we quantify the extent to which the largest connected component of a network consists of the same nodes, regardless of the specific set of deactivated links. Our results are intuitive in the case of single-layered systems: the presence of large degree nodes in a single-layered network ensures both its robustness and stability. In contrast, we find that interdependent networks that are robust to adverse events have unstable connected components. Our results bring novel insights to the design of resilient network topologies and the reinforcement of existing networked systems

Surface ligands affect photoinduced modulation of the quantum dots optical performance

ABSTRACT Changes of optical properties of the solutions of CdSe/ZnS quantum dots (QDs) covered with the trioctylphosphine oxide (TOPO) ligands under the pulsed ultraviolet (UV) laser irradiation are observed. The fluorescence quantum yield (QY) of QDs decreases by more than an order of magnitude when the radiation dose approaches 2 × 10 -15 J per particle. This process is accompanied by a blue shift of both fluorescence and the first excitonic absorption peaks. The fluorescence quenching becomes less pronounced when the overall TOPO content in the solution is increased. When ТОРО ligands are replaced with n-hexadecylamine (HDA), QY and spectral properties are not changed at the same irradiation conditions. We assume that the above changes of the optical properties are associated with photooxidation of TOPO ligands by excited QD. Such process is less probable for the HDA ligand due to its different energy structure

Near-infrared fluorescence imaging with indocyanine green in diabetic patient with critical limb ischemia: a case report

A case report of type 2 diabetic patient with critical limb ischemia (CLI) after successful endovascular revascularization is reported. The diagnosis of CLI was established according to clinical data and results of lower limb ischemia assessment by non-invasive methods. The unique feature of this case is presentation of results of the new method of lower limb ischemia assessment fluorescent angiography in near infrared range using indocyanine green (ICG). Following parameters of fluorescent angiography in near infrared range are analyzed in different regions of interest: Tstart(sec) the time of fluorescence occurrence (Istart, unit) in the analyzed area after intravenous administration of ICG; Tmax (sec) time to achieve maximum fluorescence (Imax, unit) after intravenous injection of ICG; Tmax Tstart (sec) the time difference between Imax and Istart. In this clinical case, the time of achievement Istart, Imax, Tmax Tstart in different regions of interest decreased after successful endovascular revascularization of lower limb arteries

Conjugates of Ultrasmall Quantum Dots and Acridine Derivatives as Prospective Nanoprobes for Intracellular Investigations

Designing nanoprobes in which quantum dots (QDs) are used as photoluminescent labels is an especially promising line of research due to their possible medical applications ranging from disease diagnosis to drug delivery. In spite of the significant progress made in designing such nanoprobes, the properties of their individual components, i.e., photoluminescent QDs, vectorization moieties, and pharmacological agents, still require further optimization to enhance the efficiency of diagnostic or therapeutic procedures. Here, we have developed a method of engineering compact multifunctional nanoprobes based on functional components with optimized properties: bright photoluminescence of CdSe/ZnS (core/shell) QDs, a compact and effective antitumor agent (an acridine derivative), and direct conjugation of the components via electrostatic interaction, which provides a final hydrodynamic diameter of nanoprobes smaller than 15 nm. Due to the possibility of conjugating various biomolecules with hydroxyl and carboxyl moieties to QDs, the method represents a versatile approach to the biomarker-recognizing molecule imaging of the delivery of the active substance as part of compact nanoprobes

Synthesis, physico-chemical and optical characterisation of fluorescent nanocrystals for biomedical applications.

Le développement des nanoparticules fluorescentes, appelées quantum dots (QDs) est devenu l'un des domaines les plus prometteurs de la science des matériaux. Dans cette étude une procédure de synthèse de QDs a été mise au point, comprenant la synthèse de noyaux ultra-minces de CdSe, la purification de noyau haute performance, le revêtement central avec une coquille épitaxiale en ZnS. Cette approche a permis d’obtenir des QDs d’une taille de 3,7 nm possédant un rendement quantique supérieur à 70%. Les QDs développés ont été utilisés pour concevoir des conjugués de QDs compacts avec les nouveaux dérivés d'acridine, ayant une affinité élevée pour le G-quadruplex des télomères, ainsi que leur effet inhibiteur sur la télomérase, une cible importante du traitement du cancer. Les résultats de cette étude ouvrent la voie à l'ingénierie de nanosondes multifonctionnelles possédant une meilleure pénétration intracellulaire, une plus forte brillance et une stabilité colloïdale plus importante.Development of the fluorescent nanoparticles referred to as quantum dots (QDs) has become one of the most promising areas of materials sciences. In this study, a procedure of synthesis of QDs, which includes the synthesis of ultrasmall CdSe cores, high-performance purification, core coating with an epitaxial ZnS shell has been developed. This approach has allowed obtaining 3.7-nm QDs with a quantum yield exceeding 70%. The QDs have been used: to engineer compact conjugates of QDs with the novel acridine derivatives, which have a high affinity for the telomere G-quadruplex; to demonstrate their inhibitory effect on telomerase, an important target of anticancer therapy; and to accelerate transmembrane penetration of ultrasmall QDs into cancer cells while retaining a high brightness and colloidal stability. The results of this study pave the way to the engineering of multifunctional nanoprobes with improved intracellular penetration, brightness, and colloidal stability

THE SPEED BEHAVIOR OF CZECH PROFESSIONAL DRIVERS ACCORDING TO ORDINARY VS. VARIABLE SPEED LIMIT SIGNS: AN ON-ROAD AND DRIVING SIMULATION-BASED COMPARISON

Using the speed of professional truck drivers, the effectiveness of speed limit signs was compared for 1) a temporary variable-message sign that uses LED technology and displays the current speed limit (hereinafter “VSL sign”) and 2) a normal vertical road sign with retroreflective sheeting (hereinafter “ordinary sign”). Measurements were made at two locations in the Czech Republic. Each location provided a different scenario with a different displayed speed limit on both types of signs (60 kph or 80kph). Similar measurements were made in a driving simulation. Drivers were more likely to slow down in the presence of a VSL sign than in the presence of an ordinary sign on a real road, however, no differences were found in the driving simulation. The overall results indicate that VSL signs seem to be respected more than ordinary signs in reducing professional truck drivers’ speed. Therefore, VSL signs may be beneficial as a part of a telematic system and in places with high accident risk

Řidičské styly: Klasifikace, metody výzkumu a specifika mladých řidičů

Lidský faktor je zásadní proměnnou ovlivňující bezpečnost silničního provozu. Důležitou součástí toho, jak se lidský faktor v silničním provozu projevuje, je styl, jakým řidič řídí své vozidlo. V tomto článku shrnujeme výzkum týkající se řidičských stylů mladých řidičů. Zabýváme se metodami, kterými se řidičské styly zkoumají, jako jsou např. metodyNaturalistic Driving studies. Dále popisujeme typologii řidičských stylů podle Taubman-Ben-Ari a rozebíráme souvislosti několika stylů – agresivního, bezpečného a úzkostného. V poslední části se zabýváme specifiky stylů řízení u mladých řidičů a vlivu rodičů na jejich řidičské chování. Velmi mladí řidiči mají tendenci k rizikovému chování při řízení. Tito řidiči často přejímají styl řízení od svých rodičů. Výzkum řidičských stylů a úprava asistenčních systémů vozidla tak, aby se těmto stylům přizpůsobily, může pomoci ke zvýšení bezpečnosti v dopravě a snížení emisí a celkového dopadu dopravy na životní prostředí

Conjugates of Ultrasmall Quantum Dots and Acridine Derivatives as Prospective Nanoprobes for Intracellular Investigations

International audienceDesigning nanoprobes in which quantum dots (QDs) are used as photoluminescent labels is an especially promising line of research due to their possible medical applications ranging from disease diagnosis to drug delivery. In spite of the significant progress made in designing such nanoprobes, the properties of their individual components, i.e., photoluminescent QDs, vectorization moieties, and pharmacological agents, still require further optimization to enhance the efficiency of diagnostic or therapeutic procedures. Here, we have developed a method of engineering compact multifunctional nanoprobes based on functional components with optimized properties: bright photoluminescence of CdSe/ZnS (core/shell) QDs, a compact and effective antitumor agent (an acridine derivative), and direct conjugation of the components via electrostatic interaction, which provides a final hydrodynamic diameter of nanoprobes smaller than 15 nm. Due to the possibility of conjugating various biomolecules with hydroxyl and carboxyl moieties to QDs, the method represents a versatile approach to the biomarker-recognizing molecule imaging of the delivery of the active substance as part of compact nanoprobes

Energy transfer between single semiconductor quantum dots and organic dye molecules

An understanding of the mechanisms of energy transfer and conversion on the nanoscale is one of the key requirements for an implementation of highly efficient photonic nanodevices based on hybrid organic/inorganic nanomaterials. In this work we conduct steady-state and time resolved optical studies of the emission properties of an ensembles and single semiconductor quantum dots and attached organic dye molecules. We revealed that the luminescence intensity of a hybrid structure does not follow the blinking behavior of quantum dots. We also demonstrated an efficient single photon generation from single hybrid nanostructures which involves an energy transfer from donor to acceptor as main excitation source.This work was supported by the Ministry of Education and Science of the Russian Federation under grant no. 14.Y26.31.0011. Y. R. and T. H. acknowledges support from Project Fis2016.80174-P (PLASMOQUANTA) from MINECO (Ministerio de Economiá y Competitividad), Spain.Peer reviewe