High Performance Perylenediimide-Based Copolymers and Thin Films Made Therefrom

The paper describes the synthesis and characterization of three copolymers containing perylenediimide units and other chromophores in the main chain, as well as various flexible groups as siloxane, hexafluoroisopropylidene or ether, with emphasis on their thermal and photo-optical properties. Very thin copolymer films were obtained from these polymers with smooth and homogeneous surfaces that are self-organized into vertically segregated structures. Upon irradiation with light of different wavelengths the polymers in solution showed photoluminescence maxima in the UV, blue or green-yellow spectral range. In solid state only a weak emission in the UV domain occurred due to aggregation of perylenediimide cromophores which leds to fluorescence quenching. The FRET phenomenon between oxadiazole to perylene-diimide chromophores was observed to occur for which the oxygen bridge appear to be responsible. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3507

2-{5-[2-(4-Nitro­phen­oxy)phen­yl]-1-phenyl-1H-pyrazol-3-yl}phenol

In the title compound, C27H19N3O4, the phenol and pyrazole rings are almost coplanar [dihedral angle = 0.95 (12)°] due to an intra­molecular O—H⋯N hydrogen bond, whereas the phenyl ring is tilted by 40.81 (7)° with respect to the plane of the pyrazole ring. The aromatic ring with a nitro­phen­oxy substituent makes a dihedral angle of 54.10 (7)° with the pyrazole ring

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

GÉNÉRATION D'ONDES ÉLASTIQUES PAR PRESSION DE RADIATION LASER

Des expériences récentes, effectuées aux Laboratoires du C. N. R. S. à Bellevue, ont permis la détection d'ondes élastiques initiées par la pression de radiation Laser dans divers échantillons métalliques. Une technique simple consiste à utiliser des barreaux cylindriques à faces planes parallèles (l'équivalent acoustique du Fabry-Pérot) l'une des faces étant irradiée par l'impulsion Laser, tandis que l'autre face est solidaire d'un détecteur piézoélectrique, par exemple un disque mince de titanate de barium, dont on affiche la réponse sur un tube cathodique : on constate l'apparition d'un train d'oscillations caractéristiques du phénomène de battements entre ondes élastiques de fréquences différentes. La fréquence la plus élevée (f) est déterminée par le diamètre (D) du barreau, et indépendante de la longueur, suivant l'expression : f.D = V, caractéristique d'une onde élastique transversale se propageant à la vitesse V, qu'il est possible de déterminer expérimentalement par le rapport entre la longueur (L) du barreau et le retard (Ɗt) séparant l'impulsion Laser de la réponse initiale du détecteur piézoélectrique. Les mesures effectuées sur des barreaux longs (L = 300 cm) en acier inoxydable et en aluminium sont en bon accord avec les valeurs conventionnelles des vitesses de propagation des ondes élastiques transversales dans les matériaux mentionnés. L'ensemble de ces résultats montre que la pression exercée par irradiation Laser de surfaces métalliques réfléchissantes provoque l'apparition d'ondes élastiques se propageant à l'intérieur de l'échantillon irradié, ondes dont les fréquences sont déterminées par la géométrie de l'échantillon d'une part, et la vitesse de propagation du son dans la matière considérée d'autre part.Evidence is presented of elastic waves induced in metals when irradiated with pulsed laser beams. The experimental technique is based on the acoustic equivalent of the Fabry-Perot resonator : a metal rod with plane, parallel, polished end faces. A piezoelectric transducer (ceramic disc), is attached to one face, the opposite face being irradiated by the laser beam. Variations of rod length, diameter, reflectivity of the irradiated face, also of the energy, time duration, power and cross section of the incident laser pulse are correlated with the response of the piezoelectric transducer on the screen of a double beam oscillograph. Results are presented for metal rods of a length up to 300 cm and diameter up to 2.5 cm, irradiated with conventional and Q-switched Ruby Laser pulses of 1 to 10 joules energy, focused and unfocused. The elastic waves, detected with bariurn titanate, also with PTZ discs, appear as beats between components of different frequencies. The highest frequency component (f) is correlated with the rod diameter (D) and independant of the rod length, following the relation : f.D = V, for transverse elastic wave propagation. The velocity at which the elastic wave travels down the rod (V) is given by the ratio of the rod length (L) to the time delay (Ɗt) between the laser pulse and the initial response of the piezoelectric transducer. Experimental data obtained with long rods (L = 300 cm) of stainless steel and aluminium are in good agreement with conventional values for transverse elastic wave velocity. This, and other results, shows that radiation pressure, exclusive of thermal effects, is responsible for elastic wave generation in metals irradiated by a pulsed laser beam

Synthesis and study of sulfonated poly(ether-ketone)s

An aromatic poly(ether-ketone) was prepared by the reaction of 2,2-bis(4-hydroxyphenyl)-propane with 4,4'-difluorobenzophenone and it was further sulfonated using chlorosulfonic acid and trimethylchlorosilane in 1,2-dichloroethane solution. The resulting sulfonated polymers were characterized by elemental analyses, gel permeation chromatography, infrared and H-1-NMR spectroscopy, thermogravimetric analyses and differential scanning calorimetry. Some correlations between the conditions of sulfonation reaction and the properties of the resulting polymers were made