Colour tunable electrochromic devices based on PProDOT-(Hx)2 and PProDOT-(EtHx)2 polymers

The most commonly used method to tune the colour transition states of an ECD is to modify the chemical structure of the electrochromic polymers to achieve the desired transparent to dark state switching colours. However, this approach can present significant synthetic challenges that typically result in a compromise in device performance parameters such as contrast range or stability as well as solvent processability. In this study we have investigated tuning the dark-state colour of an ECD (at +0.8 V) by solution mixing poly(3,3-dihexyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine) (PProDOT-(Hx)2), which has an excellent contrast performance but with an esthetically undesirable purple colour transition, with poly(3,3-bis(2-ethylhexyl)-3,4-dihydro-2H-thieno [3,4-b][1,4]dioxepine) (PProDOT-(EtHx)2), a material with a poorer contrast range but with more esthetic blue colour transition. The influence of mixtures of two cathodically colouring materials, PProDOT-(Hx)2 and PProDOT-(EtHx)2, on the spectroelectrochemistry and assembled ECDs was explored. Photopic contrast, electrochemical properties and the influence of the type of ionic liquid electrolyte employed in the device assembly were also investigated to determine how the dark-state colour of ECDs can be tuned while maintaining device contrast over 55%

Exploiting Intermolecular Interactions between Alkyl-Functionalized Redox-Active Molecule Pairs to Enhance Interfacial Electron Transfer

The strategies to enhance electron transfer rates between redox-active, light-harvesting molecules attached to semiconductor surfaces and redox mediators in solution by modifying molecular structure are not fully investigated yet. Therefore, the design of molecules with controlled electron transfer rates remains a challenge. The aims of this work are to quantify the effect of long alkyl chain substitution on the electron transfer from cobalt(II/III) tris(2,2′-bipyridine) to organic molecules containing carbazole and thiophene and to demonstrate that alkyl chains can be used to enhance electron transfer between donor-acceptor pairs. To this end, we study the effect of using a combination of donor and acceptor molecules with and without alkyl chains on electron transfer kinetics. Using transient absorption spectroscopy, we show that when only the molecules or the mediators have long alkyl chains, electron transfer is slightly blocked as expected. Counterintuitively, electron transfer is up to 13 times faster when long alkyl chains are attached to both the redox-active molecules and the redox mediators. The faster electron transfer is explained by an alkyl-alkyl chain interaction between the donor/acceptor, leading to the proximity (trapping) of the redox mediators close to the π-conjugated backbone of the molecules. These results suggest that intermolecular interactions can be used to enhance the electron transfer rates significantly even with well-established insulating alkyl chains attached to molecules without changing the electrochemical driving force

The influence of poly (2-methoxyaniline-5-sulfonic acid) on the electrochemical and photochemical properties of a highly luminescent ruthenium complex

Immobilisation of a luminescent material on an electrode surface is well known to substantially modulate its photophysical and electrochemical properties. Here a positively charged ruthenium metal complex ([Ru(bpy)(3)](2+)) is immobilised on all electrode surface by ion paring with a sulfonated conducting polymer poly(2-methoxyaniline-5-sulfonic acid), (PMAS). Significantly, our study reveals that the electron transport between the ruthenium metal centres can be greatly enhanced due to the interaction with the conducting polymer when both are surface confined. Charge transfer diffusion rates in the present system are an order of magnitude faster than those found where the metal centre is immobilised within a non-conducting polymeric matrix. Electron transport appears to be mediated through the PMAS conjugated structure, contrasting with the electron hopping process typically observed in non-conducting metallopolymers. This increased regeneration rate causes the ruthenium-based electrochemiluminescence (ECL) efficiency to be increased. The impact of these observations on the ECL detection of low concentrations of disease biomarkers is discussed. (c) 2007 Published by Elsevier Ltd

Maternal intrachromosomal insertional translocation leads to recurrent 1q21.3q23.3 deletion in two siblings

We identified a novel 6.33 Mb deletion of 1q21.3q23.3 (hg18; chr1: 153035245–159367106) in two siblings presenting with blepharophimosis, ptosis, microbrachycephaly, severe psychomotor, and intellectual disability. Additional common features include small corpus callosum, normal birth length and head circumference, postnatal growth restriction, low anterior hairline, upturned nose, bilateral preauricular pits, widely spaced teeth, gingival hypertrophy, left ventricular dilatation with decreased biventricular systolic function, delayed bone age, 5th finger clinodactyly, short 3rd digit, hyperconvex nails, obstructive and central sleep apnea, and bilateral heel contractures. Fluorescence in situ hybridization (FISH) performed in the mother of both children showed an apparently balanced, intrachromosomal insertional translocation of 1q21.3q23.3 to 1q42.12. The sibling recurrence likely arose by a maternal meiotic crossing over on the rearranged chromosome 1 between the deleted region and the insertion. We hypothesize that the decreased cardiac function and contractures may be related to LMNA haploinsufficiency. This case illustrates the importance of FISH when attempting to determine inheritance of a copy‐number variation and emphasize the value of evaluating known haploinsufficiency phenotypes for genes in deleted regions. © 2012 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93664/1/35563_ftp.pd

Photolithographic patterning of conducting polyaniline films via flash welding

In this work, two significant advances in photolithographic patterning of polyaniline (PANI) films are reported. Firstly, flash welding was enhanced through the use of polymeric substrates, enabling complete penetration of the welding of PANI films with thicknesses ranging from 5 to over 14 mu m, significantly thicker than reported previously. Masking of parts of the PANI films during flash welding enabled the formation of adjacent conducting and insulating regions as the welding changes the electrical properties of the film. Raman spectroscopy was used to determine the sharpness of these edges, and indicated that the interface between the flash welded and masked regions of the PANI films was typically less than 15 mu m wide. Secondly, using longpass filters, light with a wavelength less than 570 nm was found not to contribute to the welding process. This was confirmed by the use of a 635 nm laser diode for welding the PANI films. This novel approach enabled patterning of PANI films using a direct writing technique with a narrow wavelength light source

FADS2 Genetic Variance in Combination with Fatty Acid Intake Might Alter Composition of the Fatty Acids in Brain

Multiple lines of evidence suggest that fatty acids (FA) play an important role in cognitive function. However, little is known about the functional genetic pathways involved in cognition. The main goals of this study were to replicate previously reported interaction effects between breast feeding (BF) and FA desaturase (FADS) genetic variation on IQ and to investigate the possible mechanisms by which these variants might moderate BF effect, focusing on brain expression. Using a sample of 534 twins, we observed a trend in the moderation of BF effects on IQ by FADS2 variation. In addition, we made use of publicly available gene expression databases from both humans (193) and mice (93) and showed that FADS2 variants also correlate with FADS1 brain expression (P-value<1.1E-03). Our results provide novel clues for the understanding of the genetic mechanisms regulating FA brain expression and improve the current knowledge of the FADS moderation effect on cognition

Radiolabeled CCK/gastrin peptides for imaging and therapy of CCK2 receptor-expressing tumors

Cholecystokinin (CCK) receptors are overexpressed in numerous human cancers, like medullary thyroid carcinomas, small cell lung cancers and stromal ovarian cancers. The specific receptor-binding property of the endogenous ligands for these receptors can be exploited by labeling peptides with a radionuclide and using these as carriers to guide the radioactivity to the tissues that express the receptors. In this way, tumors can be visualized using positron emission tomography and single photon emission computed tomography imaging. A variety of radiolabeled CCK/gastrin-related peptides has been synthesized and characterized for imaging. All peptides have the C-terminal CCK receptor-binding tetrapeptide sequence Trp-Met-Asp-Phe-NH2 in common or derivatives thereof. This review focuses on the development and application of radiolabeled CCK/gastrin peptides for radionuclide imaging and radionuclide therapy of tumors expressing CCK receptors. We discuss both preclinical studies as well as clinical studies with CCK and gastrin peptides

WHO preferred product characteristics for monoclonal antibodies for passive immunization against respiratory syncytial virus (RSV) disease in infants - Key considerations for global use.

World Health Organization (WHO) preferred product characteristics describe preferences for product attributes that would help optimize value and use to address global public health needs, with a particular focus on low- and middle-income countries. Having previously published preferred product characteristics for both maternal and paediatric respiratory syncytial virus (RSV) vaccines, WHO recently published preferred product characteristics for monoclonal antibodies to prevent severe RSV disease in infants. This article summarizes the key attributes from the preferred product characteristics and discusses key considerations for future access and use of preventive RSV monoclonal antibodies