1,063 research outputs found

    Exposure-Tolerant Imaging Solution forCultural Heritage Monitoring

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    This paper describes a simple and cheap solution specifically designed for monitoring the degradation of thin coatings employed for metal protection. The proposed solution employs a commercial photocamera and a frequency-domain-based approach that is capable of highlighting the surface uniformity changes due to initial corrosion. Even though the proposed solution is specifically designed to monitor the long-time performance of protective coatings employed for the restoration of silver artifacts, it can be successfully used also for assessing the conservation state of other ancient metallic works of art. The proposed solution is made tolerant to exposure changes by using a procedure for sensor nonlinearity identification and correction, does not require a precise lighting control, and employs only free open-source software, so that its overall cost is very low and can be used also by not specifically trained operator

    Self-assembly of silver nanoparticles and bacteriophage

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    Biohybrid nanostructured materials, composed of both inorganic nanoparticles and biomolecules, offer prospects for many new applications in extremely diverse fields such as chemistry, physics, engineering, medicine and nanobiotechnology. In the recent years, Phage display technique has been extensively used to generate phage clones displaying surface peptides with functionality towards organic materials. Screening and selection of phage displayed material binding peptides has attracted great interest because of their use for development of hybrid materials with multiple functionalities. Here, we present a self-assembly approach for the construction of hybrid nanostructured networks consisting of M13 P9b phage clone, specific for Pseudomonas aeruginosa, selected by Phage display technology, directly assembled with silver nanoparticles (AgNPs), previously prepared by pulsed laser ablation. These networks are characterized by UV–vis optical spectroscopy, scanning/transmission electron microscopies and Raman spectroscopy. We investigated the influence of different ions and medium pH on self-assembly by evaluating different phage suspension buffers. The assembly of these networks is controlled by electrostatic interactions between the phage pVIII major capsid proteins and the AgNPs. The formation of the AgNPs-phage networks was obtained only in two types of tested buffers at a pH value near the isoelectric point of each pVIII proteins displayed on the surface of the clone. This systematic study allowed to optimize the synthesis procedure to assembly AgNPs and bacteriophage. Such networks find application in the biomedical field of advanced biosensing and targeted gene and drug delivery. Keywords: Phage display, Silver nanoparticles, Self-assembly, Hybrid architecture, Raman spectroscop

    Innovative Bioplasticizers from Residual Cynara cardunculus L. Biomass-Derived Levulinic Acid and Their Environmental Impact Assessment by LCA Methodology

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    This work compares five bioplasticizersobtained from biomass-derivedlevulinic acid in terms of their environmental impacts together withPHB-induced thermal and mechanical properties.This work is focusedon the application of Life Cycle Assessment(LCA) methodology for the quantification of the potential environmentalimpacts associated with the obtainment of levulinic acid from residual Cynara cardunculus L. biomassand its subsequent valorization in innovative bioplasticizers fortuning the properties as well as the processability of biopolymers.This potentially allows the production of fully biobased and biodegradablebioplastic formulations, thus addressing the issues related to thefossil origin and nonbiodegradability of conventional additives, suchas phthalates. Steam explosion pretreatment was applied to the epigeanresidue of C. cardunculus L. followedby a microwave-assisted acid-catalyzed hydrolysis. After purification,the as-obtained levulinic acid was used to synthesize different ketal-diesterderivatives through a three-step selective synthesis. The levulinicacid-base additives demonstrated remarkable plasticizing efficiencywhen added to biobased plastics. The LCA results were used in conjunctionwith those from the experimental activities to find the optimal compromisebetween environmental impacts and mechanical and thermal properties,induced by the bioadditives in poly(3-hydroxybutyrate), PHB biopolymer

    Analysis of background variability of honey bee colony size

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    In the context of the definition of specific protection goals for bees, risk managers asked EFSA to provide scientific background to support them in their decision‐making process about what needs to be protected and to what extent. The risk managers indicated that the derivation of a threshold of acceptable effects on colony size based on their variability was the preferred option for honey bees. This approach assumes that when evaluating a pesticide, the magnitude of acceptable effects should be set within the range of the background variability of colonies not exposed to pesticides. In this report EFSA used the BEEHAVE model to assess background variability of colony size in 19 EU environmental scenarios covering a range of geographical, climatic and beekeeping conditions. A comparison was made between the model outcome and the measurements performed on control groups of experimental field studies. The analysis of the background variability presented in this document should support risk managers in defining a threshold for colony size reduction that is considered acceptable

    Activation of cardiac renin-angiotensin system in unstable angina

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    AbstractOBJECTIVESThe aim of this study was to investigate the activity of the cardiac renin-angiotensin system (RAS) in unstable angina (UA).BACKGROUNDAngiotensin (Ang) II locally produced by continuously operating cardiac RAS may affect the pathophysiology of UA.METHODSIn 35 patients with UA, 32 with stable effort angina (SA) and 21 with atypical chest pain (controls), cardiac RAS was investigated during coronary angiography after five days of Holter monitoring by combining the measurement of aorta-coronary sinus gradient for Ang I and Ang II with the kinetics study of 125I-Ang I. Messenger RNAs (mRNA) for all the components of RAS were also quantified with the reverse transcriptase-polymerase chain reaction (RT-PCR) and localized by in situ hybridization in myocardial biopsy specimens from patients who underwent aorta-coronary bypass surgery.RESULTSCardiac Ang II generation was higher in patients with UA than it was in patients with SA or in controls (p < 0.001) due to increased de novo cardiac Ang I formation and its enhanced fractional conversion rate to Ang II. Messenger RNA levels for angiotensinogen (AGTN), angiotensin-converting enzyme (ACE) and Ang II type 1 (AT1) subtype receptors were higher in patients with UA (p < 0.01) than they were in patients with SA or in control hearts. Messenger RNAs for AGTN and ACE were almost exclusively expressed on endothelial and interstitial cells. Angiotensin II formation was correlated with ischemia burden (p < 0.001). However, the amount of Ang II formed and the expression levels of mRNAs for AGTN, ACE and AT1 were not related to the time that had elapsed since the last anginal attack.CONCLUSIONSIn patients with UA, cardiac RAS is activated, resulting in increased Ang II formation. Myocardial ischemia is essential for RAS activation, but it is unlikely to be a direct and immediate cause of RAS activation

    Definitive childlessness in women with multiple sclerosis: a multicenter study

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    The frequency of definitive childlessness in women with multiple sclerosis (MS) may be higher than in the general population. MS may also affect decisions on the delivery procedure and on breast-feeding issues. Aim of the study was to assess the frequency of childlessness and its possible causes, the proportion of cesarean deliveries (CD), and the frequency of breast-feeding in patients and controls who have reached the end of their reproductive period. Female MS patients (>43 years) and controls (>45 years) filled out a questionnaire. We enrolled 303 patients and 500 controls. MS was associated with a higher frequency of childlessness (22 vs 13%) and less patients were in a stable relationship (83 vs 89%). There was no difference in the reported rates of infertility and miscarriages, while elective abortions were more frequent in patients (20 vs 12%). MS did not significantly affect the frequency of CD or of breast-feeding. MS-related reasons for childlessness, reported by 16% of childless patients, included disability/fear of future disability, fear of genetically transmitting MS, fear of not starting/discontinuing treatments, and discouragement by physician. Definitive childlessness is more frequent in women with MS compared to controls. A portion of voluntary childlessness may be avoided through correct/tailored information to patients

    Predicting the potential distribution of aquatic herbaceous plants in oligotrophic Central Amazonian wetland ecosystems

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    Aquatic herbaceous plants are especially suitable for mapping environmental variability in wetlands, as they respond quickly to environmental gradients and are good indicators of habitat preference. We describe the composition of herbaceous species in two oligotrophic wetland ecosystems, floodplains along black-water rivers (igapo) and wetlands upon hydromorphic sand soils (campinarana) in the Parque Nacional do Jau and the Reserva de Desenvolvimento Sustentavel Uatuma in Central Amazonia, both protected areas. We tested for the potential distribution range (PDR) of the most frequent species of these ecosystems, which are the ones that occurred in at least two of the sampled wetlands, using species distribution models (SDMs). In total, 98 aquatic herbaceous species were recorded, of which 63 occurred in igapos and 44 in campinaranas. Most igapo species had ample PDRs across the Neotropics, while most campinaranas species were restricted to the Amazon Basin. These results are congruent with studies that described similar distribution patterns for tree and bird species, which emphasizes a high degree of endemism in Amazonian campinarana. However, we also found differences in the potential distribution of species between the two protected areas, indicating high environmental variability of oligotrophic ecosystems that deserve further investigation to develop effective measures for their conservation and protection

    Chromosome 9p deletion syndrome and sex reversal: novel findings and redefinition of the critically deleted regions

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    Deletions of the short arm of chromosome 9 are associated with two distinct clinical entities. Small telomeric 9p24.3 deletions cause genital anomalies in male subjects, ranging from disorder of gonadal sex to genital differentiation anomalies, while large terminal or interstitial deletions result in 9p-malformation syndrome phenotype. The critical region for non-syndromic 46,XY sex reversal was assigned to a 1 Mb interval of chromosome 9p, extending from the telomere to the DMRT genes cluster. The 9p-syndrome was assigned to bands 9p22.3p24.1, but a phenotypic map has not been established for this condition, probably because of the lack of detailed molecular and/or phenotypic characterization, as well as frequent involvement of additional chromosome rearrangements. Here, we describe a unique patient with a small isolated 9p terminal deletion, characterized by array-CGH and FISH, who shows a complex phenotype with multiple physical anomalies, resembling the 9p-syndrome, disorder of sex development with gonadoblastoma, congenital heart defect and epilepsy. The observed deletion includes the 46,XY sex-reversal critical region, excluding the region so far associated with the 9p-syndrome. Genotype-phenotype correlations are tentatively established comparing our patient to seven other previously reported males with isolated terminal 9p deletions, finely defined at a molecular level. Our observations expand the 9p deletion clinical spectrum, and add significantly to the definition of a 9p-syndrome critical region
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