Fullerene-grafted block copolymers used as compatibilizer in P3HT/PCBM bulk heterojunctions: morphology and photovoltaic performances

International audienceThe nanostructure of the active layer in polymer/fullerene bulk heterojunction solar cells is known to have a strong impact on the device performances. Controlling the polymer/fullerene blend morphology is therefore particularly important. In this work, a rod-coil block copolymer, based on a regioregular poly(3-hexylthiophene) electron-donor rod block and a C-60-grafted coil block, is used as compatibilizer and its influences on the thin film morphology as well as the photovoltaic performances are investigated. It is shown that a small fraction of compatibilizer can enhance the device performances in an otherwise non-optimized process. At higher fractions or long annealing times however, the fullerene-grafted copolymer is found to behave as a nucleation center and triggers the formation of fullerene crystals

Direct synthesis of amides from nonactivated carboxylic acids using urea as nitrogen source and Mg(NO₃)₂ or imidazole as catalysts

A new method for the direct synthesis of primary and secondary amides from carboxylic acids is described using Mg(NO3)2·6H2O or imidazole as a low-cost and readily available catalyst, and urea as a stable, and easy to manipulate nitrogen source. This methodology is particularly useful for the direct synthesis of primary and methyl amides avoiding the use of ammonia and methylamine gas which can be tedious to manipulate. Furthermore, the transformation does not require the employment of coupling or activating agents which are commonly required

Middle Neolithic farming of open-air sites in SE France: new insights from archaeobotanical investigations of three wells found at Les Bagnoles (L'Isle-sur-la-Sorgue, Dépt. Vaucluse, France)

Previous reviews of Middle Neolithic agricultural practice (4400–3500 cal bc) in southern France have highlighted a change in crop assemblages after 4000 cal bc, with a reduction of naked wheat and an increase of emmer and partly of einkorn. The recent investigation of three wells from the site of Les Bagnoles (4250–3800 cal bc) in the periphery of the southern Rhône valley yielded an unprecedented amount of waterlogged uncharred and charred plant macro remains that offer new insights into crop diversity and its changes over time. The results from the wells at Les Bagnoles were compared with other dated sunken features from open-air sites (in contrast to caves and rock shelters), with the aim of identifying patterns sug-gesting changes in the crop spectra between the early (MN1) and late (MN2) Middle Neolithic phases from taphonomically comparable contexts. The results from Les Bagnoles demonstrate that oil crops and pulses are underrepresented in dry sites and that they were a significant part of Middle Neolithic agriculture. They also indicate an increase in the representation of einkorn (instead of emmer) during MN2 that is also visible in other open-air sites. The comparison of the archaeobotani-cal results with silo storage capacity values as a proxy for average production capacity per household leads us to propose a possible drop in naked wheat productivity and opens new questions in factors affecting crop choice at the beginning of the 4th millennium cal bc

Accounting for success and failure: a discursive psychological approach to sport talk

YesIn recent years, constructionist methodologies such as discursive psychology (Edwards & Potter, 1992) have begun to be used in sport research. This paper provides a practical guide to applying a discursive psychological approach to sport data. It discusses the assumptions and principles of discursive psychology and outlines the stages of a discursive study from choice of data through to transcription and analysis. Finally, the paper demonstrates a discursive psychological analysis on sport data where athletes are accounting for success and failure in competition. The analysis demonstrates that for both success and failure, there is an apparent dilution of personal agency, to either maintain their modesty in the case of success or to manage blame when talking about failure. It is concluded that discursive psychology has much to offer sport research as it provides a methodology for in-depth studies of supporting interactions

613 cases of splenic rupture without risk factors or previously diagnosed disease: a systematic review

Background Rupture of the spleen in the absence of trauma or previously diagnosed disease is largely ignored in the emergency literature and is often not documented as such in journals from other fields. We have conducted a systematic review of the literature to highlight the surprisingly frequent occurrence of this phenomenon and to document the diversity of diseases that can present in this fashion. Methods Systematic review of English and French language publications catalogued in Pubmed, Embase and CINAHL between 1950 and 2011. Results We found 613 cases of splenic rupture meeting the criteria above, 327 of which occurred as the presenting complaint of an underlying disease and 112 of which occurred following a medical procedure. Rupture appeared to occur spontaneously in histologically normal (but not necessarily normal size) spleens in 35 cases and after minor trauma in 23 cases. Medications were implicated in 47 cases, a splenic or adjacent anatomical abnormality in 31 cases and pregnancy or its complications in 38 cases. The most common associated diseases were infectious (n = 143), haematologic (n = 84) and non-haematologic neoplasms (n = 48). Amyloidosis (n = 24), internal trauma such as cough or vomiting (n = 17) and rheumatologic diseases (n = 10) are less frequently reported. Colonoscopy (n = 87) was the procedure reported most frequently as a cause of rupture. The anatomic abnormalities associated with rupture include splenic cysts (n = 6), infarction (n = 6) and hamartomata (n = 5). Medications associated with rupture include anticoagulants (n = 21), thrombolytics (n = 13) and recombinant G-CSF (n = 10). Other causes or associations reported very infrequently include other endoscopy, pulmonary, cardiac or abdominal surgery, hysterectomy, peliosis, empyema, remote pancreato-renal transplant, thrombosed splenic vein, hemangiomata, pancreatic pseudocysts, splenic artery aneurysm, cholesterol embolism, splenic granuloma, congenital diaphragmatic hernia, rib exostosis, pancreatitis, Gaucher's disease, Wilson's disease, pheochromocytoma, afibrinogenemia and ruptured ectopic pregnancy. Conclusions Emergency physicians should be attuned to the fact that rupture of the spleen can occur in the absence of major trauma or previously diagnosed splenic disease. The occurrence of such a rupture is likely to be the manifesting complaint of an underlying disease. Furthermore, colonoscopy should be more widely documented as a cause of splenic rupture

Development of a sustainable catalytic ester amidation process

We describe the development of a sustainable ester amidation process. Base and solvent screening, combined with the application of Design of Experiments methodology was employed to identify an optimized set of reaction conditions using a sustainable protocol. Utilizing these optimized conditions, treatment of a range of ester derivatives with amino alcohols in the presence of a catalytic quantity of potassium phosphate deploying iso-propanol as solvent results in the highly efficient generation of a range of amido-alcohol derivatives in good to excellent yield, accompanied with excellent reaction mass efficiency (RME)