709 research outputs found

    High efficiency near diffraction-limited mid-infrared flat lenses based on metasurface reflectarrays

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    A limiting factor in the development of mid-infrared optics is the lack of abundant materials that are transparent, low cost, lightweight, and easy to machine. In this paper, we demonstrate a metasurface device that circumvents these limitations. A flat lens based on antenna reflectarrays was designed to achieve near diffraction-limited focusing with a high efficiency (experiment: 80%, simulation: 83%) at 45(o) incidence angle at {\lambda} = 4.6 {\mu}m. This geometry considerably simplifies the experimental arrangement compared to the common geometry of normal incidence which requires beam splitters. Simulations show that the effect of comatic aberrations is small compared to parabolic mirrors. The use of single-step photolithography allows large scale fabrication.Comment: 9 page

    Non-Specific Responsive Nanogels and Plasmonics to Design MathMaterial Sensing Interfaces: The Case of a Solvent Sensor

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    : The combination of non-specific deformable nanogels and plasmonic optical probes provides an innovative solution for specific sensing using a generalistic recognition layer. Soft polyacrylamide nanogels that lack specific selectivity but are characterized by responsive behavior, i.e., shrinking and swelling dependent on the surrounding environment, were grafted to a gold plasmonic D-shaped plastic optical fiber (POF) probe. The nanogel-POF cyclically challenged with water or alcoholic solutions optically reported the reversible solvent-to-phase transitions of the nanomaterial, embodying a primary optical switch. Additionally, the non-specific nanogel-POF interface exhibited more degrees of freedom through which specific sensing was enabled. The real-time monitoring of the refractive index variations due to the time-related volume-to-phase transition effects of the nanogels enabled us to determine the environment's characteristics and broadly classify solvents. Hence the nanogel-POF interface was a descriptor of mathematical functions for substance identification and classification processes. These results epitomize the concept of responsive non-specific nanomaterials to perform a multiparametric description of the environment, offering a specific set of features for the processing stage and particularly suitable for machine and deep learning. Thus, soft MathMaterial interfaces provide the ground to devise devices suitable for the next generation of smart intelligent sensing processes

    Single and Synergistic Effects of Fenbendazole and Metronidazole Against Subclinical Infection by Giardia duodenalis in Non-Human Primates in a Zoological Garden in Southern Italy

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    The aim of this study was to assess the single and synergistic effects of fenbendazole (Fenb) and metronidazole (Metro) for the treatment of Giardia duodenalis infection in different species of non-human primates (NHPs) housed in a zoological garden of southern Italy. Moreover, the study also aimed to better define the circulation of G. duodenalis zoonotic assemblages in NHP and the potential occurrence of zoonotic transmission between the staff from the zoo and NHP. Briefly, six species that belonged to four families (Lemuridae, Cercopithecidae, Atelidae, and Hylobatidae) of NHP and housed in six cages (CG) were identified as Giardia positive and divided into two groups. Group F (N = 16 animals) was treated with Fenb (50 mg/kg, every 24 h for 5 consecutive days) and Group M (N = 7 animals) was treated with Metro (25 mg/kg, two times a day for 5 consecutive days). After the first round of therapy, all the animals were retreated for 5 days by inverting the drugs in each group. On each sampling day [study days (SDs) 3-24], the samples were tested for the presence of Giardia cysts using the FLOTAC technique. Multiple fecal tests for the antigen detection of Giardia, such as rapid ELISA and direct immunofluorescence (IFA), were performed at each sampling point only on samples that resulted in positive for Giardia cysts with FLOTAC. The efficacy of Fenb ranged from 30 to 67% and for Metro ranged from 82 to 96%. The results showed the synergistic effects of Metro and Fenb (98-100%) over the combination of Fenb and Metro (52-90%) against the infection by Giardia in NHPs. The overall k agreement between FLOTAC and IFA was reached 0.858 (p = 0.0001). In contrast, all the samples had a negative antigen result when using ELISA. At molecular analysis, six samples were confirmed positive for Giardia by nested PCR. Only two positive samples were successfully sequenced that showed 100% of identity with assemblage B. All the samples from the humans included in the study resulted in negative for Giardia cysts. Overall, the study emphasizes the need for regular monitoring of Giardia infections in NHP housed in zoos by traditional diagnostic tools combined with molecular characterization of the parasite

    Increased endocannabinoid levels reduce the development of precancerous lesions in the mouse colon

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    Colorectal cancer is an increasingly important cause of death in Western countries. Endocannabinoids inhibit colorectal carcinoma cell proliferation in vitro. In this paper, we investigated the involvement of endocannabinoids on the formation of aberrant crypt foci (ACF, earliest preneoplastic lesions) in the colon mouse in vivo. ACF were induced by azoxymethane (AOM); fatty acid amide hydrolase (FAAH) and cannabinoid receptor messenger ribonucleic acid (mRNA) levels were analyzed by the quantitative reverse transcription polymerase chain reaction (RT-PCR); endocannabinoid levels were measured by liquid chromatography–mass spectrometry; caspase-3 and caspase-9 expressions were measured by Western blot analysis. Colonic ACF formation after AOM administration was associated with increased levels of 2-arachidonoylglycerol (with no changes in FAAH and cannabinoid receptor mRNA levels) and reduction in cleaved caspase-3 and caspase-9 expression. The FAAH inhibitor N-arachidonoylserotonin increased colon endocannabinoid levels, reduced ACF formation, and partially normalized cleaved caspase-3 (but not caspase-9) expression. Notably, N-arachidonoylserotonin completely prevented the formation of ACF with four or more crypts, which have been show to be best correlated with final tumor incidence. The effect of N-arachidonoylserotonin on ACF formation was mimicked by the cannabinoid receptor agonist HU-210. No differences in ACF formation were observed between CB1 receptor-deficient and wild-type mice. It is concluded that pharmacological enhancement of endocannabinoid levels (through inhibition of endocannabinoid hydrolysis) reduces the development of precancerous lesions in the mouse colon. The protective effect appears to involve caspase-3 (but not caspase-9) activation

    Italian guidelines for management and treatment of hyperbilirubinaemia of newborn infants ≥ 35 weeks' gestational age

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    Hyperbilirubinaemia is one of the most frequent problems in otherwise healthy newborn infants. Early discharge of the healthy newborn infants, particularly those in whom breastfeeding is not fully established, may be associated with delayed diagnosis of significant hyperbilirubinaemia that has the potential for causing severe neurological impairments. We present the shared Italian guidelines for management and treatment of jaundice established by the Task Force on Hyperbilirubinaemia of the Italian Society of Neonatology.The overall aim of the present guidelines is to provide an useful tool for neonatologists and family paediatricians for managing hyperbilirubinaemia

    Measuring transcutaneous bilirubin: a comparative analysis of three devices on a multiracial population

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    BACKGROUND: Hyperbilirubinemia can lead to potentially irreversible bilirubin-induced neurotoxicity. Transcutaneous bilirubin (TcB) determination has become a valuable aid in non invasive screening of neonatal jaundice. The aim of this study is to compare the performance of three most widespread transcutaneous bilirubinometers on a multiracial population of term and late pre-term neonates. METHODS: Bilirubin concentration was determined using traditional photometric determination and transcutaneously with Bilicheck, BiliMed and JM-103, in random order. Total serum bilirubin (TSB) was determined over a wide concentration range (15,8–0,7 mg/dl) with a mean of 9,5 mg/dl. Related TcB values using Bilicheck (TcB-BC), BiliMed (TcB-BM), and JM-103 (TcB-JM) are reported in Table 1. RESULTS: A multiracial population of 289 neonates was enrolled with a gestational age ranging from 35 to 41 weeks; birth weight ranging from 1800to 4350 grams; hours of life ranging from 4 to 424. In the total study population correlation analysis using Pearson coefficients showed good results for Bilicheck (r = 0.86) and JM-103 (r = 0.85) but poor for BiliMed (r = 0,70). Similar results were found for the non-Caucasian neonates subgroup. Bilicheck and JM-103 had a greater area under the curve than BiliMed when TSB =14 mg/dl was chosen as a threshold value both for the total study population and the non-Caucasian subgroup. CONCLUSIONS: Bilicheck and JM-103, but not BiliMed, are equally reliable screening tools for hyperbilirubinemia in our multiracial neonatal population
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