4,749 research outputs found

    Scattering lengths and universality in superdiffusive L\'evy materials

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    We study the effects of scattering lengths on L\'evy walks in quenched one-dimensional random and fractal quasi-lattices, with scatterers spaced according to a long-tailed distribution. By analyzing the scaling properties of the random-walk probability distribution, we show that the effect of the varying scattering length can be reabsorbed in the multiplicative coefficient of the scaling length. This leads to a superscaling behavior, where the dynamical exponents and also the scaling functions do not depend on the value of the scattering length. Within the scaling framework, we obtain an exact expression for the multiplicative coefficient as a function of the scattering length both in the annealed and in the quenched random and fractal cases. Our analytic results are compared with numerical simulations, with excellent agreement, and are supposed to hold also in higher dimensionsComment: 6 pages, 8 figure

    How the mere desire for certainty can lead to a preference for men in authority (particularly among political liberals)

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    Women are harmed by stereotypes about their fit for positions of authority and changing these stereotypes is not a simple task. As stereotypes have strong epistemic properties, individuals with a high need for cognitive closure (NCC; i.e., the desire for epistemic certainty) can be more likely to accept these stereotypes and, consequently, to prefer men in positions of authority. Consistent with the reactive liberal hypothesis, this effect could be actually more visible among individuals with both a high NCC and left-wing political orientations. We supported these hypotheses in a series of three studies. In Study 1 (N = 217), we found that manipulated NCC predicted preference for men in authority through stereotypes of women as not being fit for authority in a measurement-of-mediation design. In Study 2 (N = 151), we supported this effect in a mediation-as-process design. In Study 3 (N = 391), we found the indirect NCC effect on preference for men in authority was more visible among political liberals. A major implication of this work is that ways of changing the effect of these stereotypes should take into account the NCC, but particularly among individuals with left-wing beliefs

    Treatment of high strength industrial wastewater with membrane bioreactors for water reuse: Effect of pre-treatment with aerobic granular sludge on system performance and fouling tendency

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    In this study, the treatment of citrus wastewater with membrane bioreactors (MBRs) under different configurations was investigated for water reuse. In particular, one MBR and one aerobic granular sludge MBR (AGS+MBR) bench scale plants were operated for 60 days. The experimental campaign was divided into two periods. In Phase I, a conventional hollow fiber MBR was employed for the treatment of the raw high strength wastewater, whereas in Phase II a combination of in-series reactors (AGS plus MBR) was adopted for the treatment of the high strength citrus wastewater The results demonstrated that both plant configurations enabled very high COD removal, with average values close to 99%. Respirometric batch tests revealed a considerable high metabolic activity of the biomass in both plant configurations, with higher values in the AGS+MBR. It was speculated that the MBR reactor enriched in active biomass deriving from the erosion of the external granule layers in the upstream reactor. In terms of fouling tendency, higher resistance to filtration was observed in the AGS+MBR plant, also characterized by higher irremovable resistance increase compared to the MBR plant that might severely affect the membrane service life

    The Mediational Role of Desire for Cultural Tightness on Concern With COVID-19 and Perceived Self-Control

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    When ecological threats are more severe or prevalent, societies are more likely to tighten their social norms and punishments. Moreover, when people follow clear and tight rules, they are more prone to regulate their behavior (i.e., self-control) in order to avoid punishment. Therefore, we examined the mediating role of people’s endorsement of cultural tightness (i.e., support and desire) on the relationship between concern with COVID-19 threat and personal self-control. Our hypothesis was tested through a mediation model in two studies with a sample of (N=315, 77.1% females, Mage=23.71) university students (Study 1) and with a heterogeneous sample of (N=239, 65.7% females, Mage=36.55) participants (Study 2). Empirical support for the proposed model was found in both studies. Implications of this research will be discussed. The main implication is related to the possibility that people’s desire for strong norms to cope with the COVID-19 threat could promote greater self-regulated preventive behavior in order to protect their health

    Mechanistic insights into the release of doxorubicin from graphene oxide in cancer cells

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    Liposomal doxorubicin (L-DOX) is a popular drug formulation for the treatment of several cancer types (e.g., recurrent ovarian cancer, metastatic breast cancer, multiple myeloma, etc.), but poor nuclear internalization has hampered its clinical applicability so far. Therefore, novel drug-delivery nanosystems are actively researched in cancer chemotherapy. Here we demonstrate that DOX-loaded graphene oxide (GO), GO-DOX, exhibits much higher anticancer efficacy as compared to its L-DOX counterpart if administered to cellular models of breast cancer. Then, by a combination of live-cell confocal imaging and fluorescence lifetime imaging microscopy (FLIM), we suggest that GO-DOX may realize its superior performances by inducing massive intracellular DOX release (and its subsequent nuclear accumulation) upon binding to the cell plasma membrane. Reported results lay the foundation for future exploitation of these new adducts as high-performance nanochemotherapeutic agents

    Chitosan-tripolyphosphate nanoparticles designed to encapsulate polyphenolic compounds for biomedical and pharmaceutical applications - A Review  

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    Plant-based polyphenols are natural compounds, present in fruits and vegetables. During recent years, polyphenols have gained special attention due to their nutraceutical and pharmacological activities for the prevention and treatment of human diseases. Nevertheless, their photosensitivity and low bioavailability, rapid metabolism and short biological half-life represent the major limitations for their use, which could be overcome by polyphenols encapsulation (flavonoids and non-flavonoids) into chitosan (CS)-tripolyphosphate (TPP) based nanoparticles (NP). In this review, we particularly focused on the ionic gelation method for the NP design. This contribution exhaustively discusses and compares results of scientific reports published in the last decade referring to ionic gelation applied for the protection, controlled and site-directed delivery of polyphenols. As a consequence, CS-TPP NP would constitute true platforms to transport polyphenols, or a combination of them, to be used for the designing of a new generation of drugs or nutraceuticals.Fil: Di Santo, Mariana Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: D' Antoni, Cecilia Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Domínguez Rubio, Ana Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Alaimo, Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Perez, Oscar Edgardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentin

    Analisi oncologica e delle complicanze nel trattamento endoscopico mediante laser CO2 dei tumori glottici in classe T1-T2: la nostra esperienza

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    Esistono numerose strategie terapeutiche per il trattamento del carcinoma glottico in stadio iniziale (Tis/T1/T2): la laringectomia parziale a cielo aperto, la radioterapia e la chirurgia endoscopica condotta mediante laser CO2. In particolare quest’ultimo approccio ha gradualmente, ma inesorabilmente, acquisito un ruolo sempre più centrale nel management del cancro laringeo. In questo lavoro presentiamo la nostra esperienza in materia di chirurgia endoscopica laser-assistita delle neoplasie glottiche in stadio iniziale. è stata realizzata un’analisi retrospettiva su un campione di 72 pazienti affetti da carcinoma glottico in classe T1-T2 trattati con cordectomia laser endoscopica nel periodo compreso tra il 2006 e il 2012. Tutti i pazienti avevano almeno 36 mesi di follow-up. La disease-specific survival, la disease-free survival (DFS) e il tasso di preservazione laringea rilevati con il presente studio sono stati rispettivamente del 98,6%, 84,7% e 97,2%. Analizzando l’influenza sull’outcome oncologico a lungo termine di alcune tra le principali caratteristiche della malattia o del trattamento eseguito, abbiamo riscontrato come il coinvolgimento da parte del tumore della commissura anteriore e lo staging patologico della neoplasia (pT) correlino significativamente con un aumentato tasso di recidiva locale (p = 0,021 e p = 0,035) e con una ridotta DFS (p = 0,017 e p = 0,023). Gli altri parametri presi in esame, come staging clinico, tipo di cordectomia, coinvolgimento di altre specifiche sottosedi laringee e stato dei margini di resezione, non si sono dimostrati, invece, correlare significativamente con gli endpoint oncologici stabiliti. La chirurgia endoscopica laser-assistita è quindi una tecnica estremamente affidabile per il trattamento dei tumori glottici in stadio iniziale in termini di outcome oncologico. Il tasso di recidiva risulta significativamente influenzato dal coinvolgimento della commissura anteriore e dal pT

    Two forms of short-interval intracortical inhibition in human motor cortex

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    Background: Pulses of transcranial magnetic stimulation (TMS) with a predominantly anterior-posterior (AP) or posterior-anterior (PA) current direction over the primary motor cortex appear to activate distinct excitatory inputs to corticospinal neurons. In contrast, very few reports have examined whether the inhibitory neurons responsible for short-interval intracortical inhibition (SICI) are sensitive to TMS current direction. Objectives: To investigate whether SICI evaluated with AP and PA conditioning stimuli (CSPA and CSAP) activate different inhibitory pathways. SICI was always assessed using a PA-oriented test stimulus (TSPA). Methods: Using two superimposed TMS coils, CSPA and CSAP were applied at interstimulus intervals (ISI) of 1–5 ms before a TSPA, and at a range of different intensities. Using a triple stimulation design, we then tested whether SICI at ISI of 3 ms using opposite directions of CS (SICICSPA3 and SICICSAP3) interacted differently with three other forms of inhibition, including SICI at ISI of 2 ms (SICICSPA2), cerebellum-motor cortex inhibition (CBI 5 ms) and short-latency afferent inhibition (SAI 22 ms). Finally, we compared the effect of tonic and phasic voluntary contraction on SICICSPA3 and SICICSAP3. Results: CSAP produced little SICI at ISIs = 1 and 2 ms. However, at ISI = 3 ms, both CSAP and CSPA were equally effective at the same percent of maximum stimulator output. Despite this apparent similarity, combining SICICSPA3 or SICICSAP3 with other forms of inhibition led to quite different results: SICICSPA3 interacted in complex ways with CBI, SAI and SICICSPA2, whereas the effect of SICICSAP3 appeared to be quite independent of them. Although SICICSPA and SICICSAP were both reduced by the same amount during voluntary tonic contraction compared with rest, in a simple reaction time task SICICSAP was disinhibited much earlier following the imperative signal than SICICSPA. Conclusions: SICICSPA appears to activate a different inhibitory pathway to that activated by SICICSAP. The difference is behaviourally relevant since the pathways are controlled differently during volitional contraction. The results may explain some previous pathological data and open the possibility of testing whether these pathways are differentially recruited in a range of tasks
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