86,705 research outputs found
Y-shaped alkynylimidazoles as effective push-pull fluorescent dyes for luminescent solar concentrators (LSCs)
No full textThe synthesis of three 2-arylalkynyl-4,5-diarylimidazoles endcapped with typical electron-donating (ED) and electron-withdrawing (EW) groups (push-pull system) and their evaluation as fluorescent dyes for thin-film luminescent solar concentrators (LSCs) is described. These novel Y-shaped imidazole-based fluorophores were easily assembled in good chemical yields through a three-step synthetic sequence involving a double Suzuki arylation, followed by a dehydrogenative alkynylation, and a Knoevenagel condensation. Their optical and spectroscopic properties were analyzed both in solution and in poly(methyl methacrylate) (PMMA) films. All the molecules in PMMA films showed an intense, red-shifted emission between 540 and 575 nm with large Stokes shift (>120 nm), moderate-to-good fluorescence quantum yields (QY) and good device efficiencies (ηdev), especially for compound 3
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Computational Design, Synthesis, and Mechanochromic Properties of New Thiophene-Based pi-Conjugated Chromophores
No full textThe possibility of exploiting supramolecular architectures for the preparation of innovative mechano- chromic devices has been extended by designing novel thienyl-substituted 1,4- bis-(ethynyl)benzene dyes, which are characterized by a conjugated, rigid, rodlike core structure. This new family of chromophores was synthesized ac- cording to a simple two-step sequential cross-coupling reaction, and the optical properties were investigated in solution and in a polymeric matrix. To tune the mechanochromic performances in smart polymer materials, a virtual screening was set up that was able to select a derivative with optimal spectral features. The effective combination of experimental and computational inves- tigations allowed us to spot those ho- mologues with already potential aniso- tropic and aggregachromic features and characterized by the best spectral prop- erties and luminescent response. The best candidate was synthesized and dis- persed into a polyethylene matrix, indeed achieving an “in silico de- signed” mechanochromic material. Be- sides the specific applications of this novel material, the integration of com- putational and experimental techniques reported here defines an efficient pro- tocol that can be applied to make a se- lection among similar dye candidates, which constitute the essential respon- sive part of such supramolecular devices
[Newspaper Clipping: Author Claims Evidence of Second JFK Assassin #1]
No full textNewspaper article titled "Author Claims Evidence of Second JFK Assassin." The article states that author Richard J. Whalen concluded "that there is circumstantial evidence to support the theory of a second assassin in the shooting of President John F. Kennedy.
Also By The Same Author: AKTiveAuthor, a Citation Graph Approach to Name Disambiguation
No full textThe desire for definitive data and the semantic web drive for inference over heterogeneous data sources requires co-reference resolution to be performed on those data. In particular, name disambiguation is required to allow accurate publication lists, citation counts and impact measures to be determined. This paper describes a graph-based approach to author disambiguation on large-scale citation networks. Using self-citation, co-authorship and document source analyses, AKTiveAuthor clusters papers, achieving precision of 0.997 and recall of 0.818 over a test group of eight surname clusters
John F. Kennedy telegram to Roosevelt
No full textJersey Homesteads (later the Borough of Roosevelt) was established in the 1930s as an agro-industrial cooperative community. It was established specifically for urban Jewish garment workers, many of whom had emigrated from Europe. President John F. Kennedy sent a telegram to the citizens of Roosevelt, New Jersey, apologizing for not being able to attend the memorial dedication in honor of former President Franklin Delano Roosevelt. (Jersey Homesteads became Roosevelt in 1945 in honor of the president.) President Kennedy expressed his gratitude to the people of Roosevelt for constructing the memorial, and commented that it will serve as a constant reminder of Roosevelt's good works
CoolSun: organic paints for cool buildings
No full textPoor attention has been paid so far to the 50% of NIR radiation flux (750-2500 nm), coming from direct, diffused and reflected sun radiation, which contributes to increase the temperature in urban areas. To reduce the increasing demand for energy consumption for air conditioning or to produce cool fabrics, there is a need for NIR reflective pigments and coatings formulation since reflecting the sun’s radiation minimizes the amount of energy absorbed by the surface1. NIR reflective property is useful in applications where solar heating must be attenuated, such as leather goods, greenhouse coverings, roofing and transporting of heat-sensitive materials2 Today, NIR reflectivity is obtained with the use of inorganic pigments (TiO2, metal oxides and complexes) that are expensive and, in some cases, toxic2. The challenge is the development of a fully organic NIR reflective coating. This can be possible by mixing NIR non-absorbing pigments with polymeric NIR-reflective additives in the formulation of coatings.
This work aims at the preparation of paints starting from waterborne-dispersion of resin and NIR reflective organic pigments and additives. As pigment we used different perylene bis-imide derivatives, already known for their NIR reflective properties4. Aswell, we studied the synergic cool effect adding thermoplastic hollow microspheres (Expancel®)5 and their comparison with a standard black dye
Modeling, preparation and characterization of new fluorophores for smart polymer composite films
No full textPolymer composite films containing dyes of different structure characterized by optical responsiveness to external stimuli are studied because they are very promising for the development of smart and intelligent polymer devices for sensing and safety applications.
In this context, a computational work was carried out for the screening of UV-Vis absorption and emission spectra of a series of fluorophores containing functionalized thiophene rings with push-pull groups.
The theoretical most promising structures, based on new 1,4-bis-(thienylethynyl)benzene derivatives, were synthesized by a two-step sequence involving a Cassar-Heck coupling reaction followed by a Sila-Sonogashira reaction and and their main optical features were characterized in solution by UV-Vis and emission spectroscopies
A Morpho-Molecular Diagnosis of Papillary Thyroid Carcinoma: BRAF V600E Detection as an Important Tool in Preoperative Evaluation of Fine-Needle Aspirates
No full textBACKGROUND:
Although most thyroid nodule fine-needle aspiration (FNA) diagnoses are definitive or nearly definitive, about 30% of them are not read as definitively benign or malignant, the so-called indeterminate or suspicious FNA diagnosis. The prevalence of malignancy in FNA samples with these diagnoses varies from 10% to 52%. The first aim of this study was to determine if BRAF V600E analysis of thyroid FNA cytological smears could be performed with a relatively simple protocol. We also sought to determine if assessing the presence of BRAF gene mutations in preoperative FNA cytology slides would provide diagnostic information for FNA samples with a reading of indeterminate or suspicious thyroid lesions.
METHODS:
DNA was extracted directly from FNA-stained smears of 111 patients with thyroid lesions having different cytological diagnoses. There was 1 cystic nodule, 20 microfollicular proliferations without atypia, 32 that were suspicious for papillary carcinoma, 56 papillary thyroid carcinomas (PTC), and 2 poorly differentiated carcinomas. The BRAF V600E mutational status was determined by sequencing analysis in all patients. The histopathological diagnosis was obtained in all cases.
RESULTS:
We observed that 56/90 (62.3%) patients received a definitive diagnosis of PTC when only cytology was used. After molecular analysis, the BRAF V600E mutation was detected in 18/32 (56.2%) cases with a cytology of suspicious for papillary carcinoma and 41/56 (73.2%) with PTC. According to the morpho-molecular analysis (i.e., traditional cytology combined with BRAF V600E analysis) 74/90 (82.2%) patients could be assigned a definitive diagnosis of PTC. Therefore, the addition of molecular analysis yielded an increase of 20% in the sensitivity compared to cytology alone.
CONCLUSIONS:
The method of molecular analysis of thyroid FNA smears described here can be easily performed after the FNA, thereby avoiding inconvenience and additional time during the FNA and permitting later analysis of samples having indeterminate cytology features. The increased sensitivity of this preoperative morpho-molecular analysis should provide information that is useful in deciding the extent of thyroid surgery for thyroid nodules that are indeterminate or suspicious on cytology
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