1,719 research outputs found

    Photo-induced curing of thymine-based bioinspired polymers. A chemometric analysis

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    The curing process of new materials based on styrene monomers functionalized with thymine and charged ionic groups was studied using UV-vis spectroscopy in combination with chemomet-ric models. The effect of the copolymer molecular weight on the immobilization point was analyzed. The evolution of the curing process of the copolymer (4-vinylbenzyl) thymine (VBT) -vinylbenzyl triethyl ammonium chloride (VBA) involved three species, which absorb in the spectral region analyzed. The contributions of each species to the total signal at each irradiation time were determined, and the ki-netic constant of the crosslinking reaction was esti-mated. The study allowed evaluating the consistency of the chemometric decomposition, obtaining a rea-sonable correlation between the frequency spectra and the time evolution calculated with the algorithm. The chemometric analysis showed to be a powerful tool to provide complementary information on photo-induced immobilization of VBT-VBA films, which is crucial for developing new environmentally benign materials and new energy-saving methods.Fil: Bortolato, Santiago Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Salta. Instituto de Investigación para la Industria Química (i); ArgentinaFil: Barbarini, Alejandro Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Salta. Instituto de Investigación para la Industria Química (i); ArgentinaFil: Benitez, R. M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Salta. Instituto de Investigación para la Industria Química (i); ArgentinaFil: Martino, Debora Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Salta. Instituto de Investigación para la Industria Química (i); ArgentinaFil: Estenoz, Diana Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Salta. Instituto de Investigación para la Industria Química (i); Argentin

    Expression and cellular localization of the transcription factor NeuroD1 in the developing and adult rat pineal gland

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    Circadian rhythms govern many aspects of mammalian physiology. The daily pattern of melatonin synthesis and secretion is one of the classic examples of circadian oscillations. It is mediated by a class of neuroendocrine cells known as pinealocytes which are not yet fully defined. An established method to evaluate functional and cytological characters is through the expression of lineage‐specific transcriptional regulators. NeuroD1 is a basic helix‐loop‐helix transcription factor involved in the specification and maintenance of both endocrine and neuronal phenotypes. We have previously described developmental and adult regulation of NeuroD1 mRNA in the rodent pineal gland. However, the transcript levels were not influenced by the elimination of sympathetic input, suggesting that any rhythmicity of NeuroD1 might be found downstream of transcription. Here, we describe NeuroD1 protein expression and cellular localization in the rat pineal gland during development and the daily cycle. In embryonic and perinatal stages, protein expression follows the mRNA pattern and is predominantly nuclear. Thereafter, NeuroD1 is mostly found in pinealocyte nuclei in the early part of the night and in cytoplasm during the day, a rhythm maintained into adulthood. Additionally, nocturnal nuclear NeuroD1 levels are reduced after sympathetic disruption, an effect mimicked by the in vivo administration of α‐ and β‐adrenoceptor blockers. NeuroD1 phosphorylation at two sites, Ser274 and Ser336, associates with nuclear localization in pinealocytes. These data suggest that NeuroD1 influences pineal phenotype both during development and adulthood, in an autonomic and phosphorylation‐dependent manner.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111177/1/jpi12228.pd

    Measuring how communication and engagement efforts help deliver outcomes

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    Key messages Initial steps towards outcome-focused monitoring, evaluation & learning (MEL) on communication and engagement can be small, but they must be systematic. To achieve broad participation, MEL needs to be lean and do-able. Well-designed MEL adds value by feeding information and lessons into future work and decision-making. Adequate time must be devoted to embedding MEL into the initial activity plan and following it throughout the communication engagement activity and afterwards. MEL is easier when it is done more often. It is helpful to draw upon resource persons. Preparatory work and capturing feedback through mechanisms built into the communication- engagement activity is more informative than soliciting responses afterwards. Peer exchanges about MEL practices and adaptable templates are beneficial. Aligning specific communication activities with the established impact pathway can ensure more strategic and focused activities and products that contribute to outcomes and impact

    Stress relaxation and creep experiments with the atomic force microscope: a unified method to calculate elastic moduli and viscosities of biomaterials (and cells)

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    We show that the atomic force microscope can perform stress relaxation and creep compliance measurements on living cells. We propose a method to obtain the mechanical properties of the studied biomaterial: the relaxation time, the elastic moduli and the viscosity.Comment: 17 pages, three figure

    Effect of ABCB1 and ABCC3 Polymorphisms on Osteosarcoma Survival after Chemotherapy: A Pharmacogenetic Study

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    Standard treatment for osteosarcoma patients consists of a combination of cisplatin, adriamycin, and methotrexate before surgical resection of the primary tumour, followed by postoperative chemotherapy including vincristine and cyclophosphamide. Unfortunately, many patients still relapse or suffer adverse events. We examined whether common germline polymorphisms in chemotherapeutic transporter and metabolic pathway genes of the drugs used in standard osteosarcoma treatment may predict treatment response. METHODOLOGY/PRINCIPAL FINDINGS: In this study we screened 102 osteosarcoma patients for 346 Single Nucleotide Polymorphisms (SNPs) and 2 Copy Number Variants (CNVs) in 24 genes involved in the metabolism or transport of cisplatin, adriamycin, methotrexate, vincristine, and cyclophosphamide. We studied the association of the genotypes with tumour response and overall survival. We found that four SNPs in two ATP-binding cassette genes were significantly associated with overall survival: rs4148416 in ABCC3 (per-allele HR = 8.14, 95%CI = 2.73-20.2, p-value = 5.1x10(-)(5)), and three SNPs in ABCB1, rs4148737 (per-allele HR = 3.66, 95%CI = 1.85-6.11, p-value = 6.9x10(-)(5)), rs1128503 and rs10276036 (r(2) = 1, per-allele HR = 0.24, 95%CI = 0.11-0.47 p-value = 7.9x10(-)(5)). Associations with these SNPs remained statistically significant after correction for multiple testing (all corrected p-values [permutation test] </= 0.03). CONCLUSIONS: Our findings suggest that these polymorphisms may affect osteosarcoma treatment efficacy. If these associations are independently validated, these variants could be used as genetic predictors of clinical outcome in the treatment of osteosarcoma, helping in the design of individualized therapy

    Surface nanopatterning of metal thin films by physical vapour deposition onto surface-modified silicon nanodots

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    Nanostructuring of metallic and semiconductor surfaces in the sub-100 nm range is a key point in the development of future technologies. In this work we describe a simple and low-cost method for metal nanostructuring with 50 nm lateral and 6 nm vertical resolutions based on metal film deposition on a silane-derivatized nanostructured silicon master. The silane monolayer anti-sticking properties allow nanopattern transfer from the master to the deposited metal films as well as easy film detachment. The method is non-destructive, allowing the use of the derivatized master several times without damaging. Potential applications of the method are in the field of high-density data storage, heterogeneous catalysis and electrocatalysis, microanalysis (sensors and biosensors) and new optical devices.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada
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