8,763 research outputs found

    Magnetic force microscopy investigation of arrays of nickel nanowires and nanotubes

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    The magnetic properties of arrays of nanowires (NWs) and nanotubes (NTs), 150 nm in diameter, electrodeposited inside nanoporous polycarbonate membranes are investigated. The comparison of the nanoscopic magnetic force microscopy (MFM) imaging and the macroscopic behavior as measured by alternating gradient force magnetometry (AGFM) is made. It is shown that MFM is a complementary technique that provides an understanding of the magnetization reversal characteristics at the microscopic scale of individual nanostructures. The local hysteresis loops have been extracted by MFM measurements. The influence of the shape of such elongated nanostructures on the dipolar coupling and consequently on the squareness of the hysteresis curves is demonstrated. It is shown that the nanowires exhibit stronger magnetic interactions than nanotubes. The non-uniformity of the magnetization states is also revealed by combining the MFM and AGFM measurements.Comment: 7 pages, 5 figure

    Toxic effect of antibiotics in grapevine (Vitis vinifera 'Albariño') for embryo emergence and transgenic plant regeneration from embryogenic cell suspension

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    Regeneration of grapevine (Vitis vinifera L.) from embryogenic cultures after gene transfer is traditionally linked to a selection procedure using antibiotic containing media. The neomycin phosphotransferase II (npt-II) and hygromycin phosphotransferase (hpt) genes that confer resistance to the antibiotics kanamycin and hygromycin, respectively, have been the selectable marker genes most frequently used for selection of transgenic grapevines. In this work, the phytotoxic effects on embryo development and plant growth of these two antibiotics were examined in 'Albariño'. Embryogenic cell suspensions were evaluated based on a twostep strategy using untransformed and transformed tissues. The phytotoxic effect was significantly different at 20 mg∙L-1 (and higher) for kanamycin and at 5 mg∙L-1 (and higher) for hygromycin. Minimal killing concentrations of kanamycin and hygromycin for 'Albariño' cell suspensions were 50 and 12.5 mg∙L-1, respectively. Embryogenic cell suspensions were bombarded using the biolistic system with the construct pBI426, harboring the selectable npt-II gene, and incubated on kanamycin containing media to determine the best inhibitory concentration allowing embryo and shoot development of only transgenic events. Only 20 % of PCR-positive transgenic embryos and 20 % of plant regeneration resulted from embryos emerged on 30 mg∙L-1. However, 80 % of PCR-positive transgenic embryos but only 10 % of plant regeneration were obtained from embryos emerged on 40 mg∙L-1. The method described, based in untransformed and transformed plant material, could be used to determine the optimal antibiotic concentration for other V. vinifera cultivars for efficient selection and regeneration of transgenic events.

    Patient information after hospitalization improves humanistic care in intensive care units

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    Introduction The purpose of the study was to assess the prognosis value of pro-adrenomedullin (pADM), C-reactive protein (CRP) and procalcitonin (PCT), lactate (LT), albumin (ALB), cholesterol (CHOL), white blood cell (WBC) and severity score in patients with severe sepsis or septic shock. Methods A prospective, observational study in adult patients with severe sepsis or septic shock in a polyvalent ICU. Demographics, severity scores (APACHE II and SOFA) and all of the biomarkers were studied within 24+ hours from septic shock onset. Descriptive and comparative statistical analysis was performed using the statistical software packages SPSS v.15 and MedCalc® 9.2.1.0. Conclusion The protein pADM, LT and ALB showed good prognosis accuracy when measured on admission of septic patients to the ICU.Ye

    Functional assessment of cancer therapy questionnaire for breast cancer (FACT-B+4): Italian version validation

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    BACKGROUND: Improvements in breast cancer diagnosis and treatment led to an increased incidence of survivors' rate. The healthcare system has to face new problems related not only to the treatment of the disease, but also to the management of the quality of life after the diagnosis. The aim of this study was to validate the Italian version of the Functional Assessment of Cancer Therapy - Breast (FACT-B+4) questionnaire and to evaluate its reliability. METHODS: The questionnaire was administered twice, with an interval of three days between each administration, to a cohort of women of the Breast Surgical Unit, PoliclincoUmberto I. Cronbach's alpha was used as a measure of the internal consistency of the Italian version. RESULTS: The Italian version of the tool was administered to 55 subjects. The Cronbach's alpha for most scores registered values >0.7, both at baseline and at the follow-up analysis, therefore the subscale showed good internal consistency. CONCLUSIONS: The Italian version of FACT-B+4 demonstrated acceptable reliability properties in the Breast Unit patients. The use of this questionnaire seemed to be effective and in line with the results derived from the English and Spanishversions. Internal consistency and validity had similar performance results

    On Randomness in Quantum Mechanics

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    The quantum mechanical probability densities are compared with the probability densities treated by the theory of random variables. The relevance of their difference for the interpretation of quantum mechanics is commented

    Activated protein C, severe sepsis and 28-day mortality

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    Protein C (PC) de ciency is prevalent in severe sepsis, studies showing that more than 80% of patients with severe sepsis have a baseline PC level below the lower limit of normal [1,2]. The aim of the study was to relate the anticoagulation activity evaluated by PC, with clinical parameters and 28-day mortality.Ye

    Adapting cognitive diagnosis computerized adaptive testing item selection rules to traditional item response theory

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    Currently, there are two predominant approaches in adaptive testing. One, referred to as cognitive diagnosis computerized adaptive testing (CD-CAT), is based on cognitive diagnosis models, and the other, the traditional CAT, is based on item response theory. The present study evaluates the performance of two item selection rules (ISRs) originally developed in the CD-CAT framework, the double Kullback-Leibler information (DKL) and the generalized deterministic inputs, noisy and gate model discrimination index (GDI), in the context of traditional CAT. The accuracy and test security associated with these two ISRs are compared to those of the point Fisher information and weighted KL using a simulation study. The impact of the trait level estimation method is also investigated. The results show that the new ISRs, particularly DKL, could be used to improve the accuracy of CAT. Better accuracy for DKL is achieved at the expense of higher item overlap rate. Differences among the item selection rules become smaller as the test gets longer. The two CD-CAT ISRs select different types of items: items with the highest possible a parameter with DKL, and items with the lowest possible c parameter with GDI. Regarding the trait level estimator, expected a posteriori method is generally better in the first stages of the CAT, and converges with the maximum likelihood method when a medium to large number of items are involved. The use of DKL can be recommended in low-stakes settings where test security is less of a concern

    Olive Oil Phenolic Compounds’ Activity against Age-Associated Cognitive Decline: Clinical and Experimental Evidence

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    Epidemiological studies have shown that consuming olive oil rich in phenolic bioactive compounds is associated with a lower risk of neurodegenerative diseases and better cognitive performance in aged populations. Since oxidative stress is a common hallmark of age-related cognitive decline, incorporating exogenous antioxidants could have beneficial effects on brain aging. In this review, we firstly summarize and critically discuss the current preclinical evidence and the potential neuroprotective mechanisms. Existing studies indicate that olive oil phenolic compounds can modulate and counteract oxidative stress and neuroinflammation, two relevant pathways linked to the onset and progression of neurodegenerative processes. Secondly, we summarize the current clinical evidence. In contrast to preclinical studies, there is no direct evidence in humans of the bioactivity of olive oil phenolic compounds. Instead, we have summarized current findings regarding nutritional interventions supplemented with olive oil on cognition. A growing body of research indicates that high consumption of olive oil phenolic compounds is associated with better preservation of cognitive performance, conferring an additional benefit, independent of the dietary pattern. In conclusion, the consumption of olive oil rich in phenolic bioactive compounds has potential neuroprotective effects. Further research is needed to understand the underlying mechanisms and potential clinical applications
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