A Genotype-First Approach for the Molecular and Clinical Characterization of Uncommon De Novo Microdeletion of 20q13.33

Background: Subtelomeric deletions of the long arm of chromosome 20 are rare, with only 11 described in the literature. Clinical features of individuals with these microdeletions include severe limb malformations, skeletal abnormalities, growth retardation, developmental and speech delay, mental retardation, seizures and mild, non-specific dysmorphic features. Methodology/Principal Findings: We characterized microdeletions at 20q13.33 in six individuals referred for genetic evaluation of developmental delay, mental retardation, and/or congenital anomalies. A comparison to previously reported cases of 20q13.33 microdeletion shows phenotypic overlap, with clinical features that include mental retardation, developmental delay, speech and language deficits, seizures, and behavior problems such as autistic spectrum disorder. There does not appear to be a clinically recognizable constellation of dysmorphic features among individuals with subtelomeric 20q microdeletions. Conclusions/Significance: Based on genotype-phenotype correlation among individuals in this and previous studies, we discuss several possible candidate genes for specific clinical features, including ARFGAP1, CHRNA4 and KCNQ2 and neurodevelopmental deficits. Deletion of this region may play an important role in cognitive development

Outcomes following small bowel obstruction due to malignancy in the national audit of small bowel obstruction

Introduction Patients with cancer who develop small bowel obstruction are at high risk of malnutrition and morbidity following compromise of gastrointestinal tract continuity. This study aimed to characterise current management and outcomes following malignant small bowel obstruction. Methods A prospective, multicentre cohort study of patients with small bowel obstruction who presented to UK hospitals between 16th January and 13th March 2017. Patients who presented with small bowel obstruction due to primary tumours of the intestine (excluding left-sided colonic tumours) or disseminated intra-abdominal malignancy were included. Outcomes included 30-day mortality and in-hospital complications. Cox-proportional hazards models were used to generate adjusted effects estimates, which are presented as hazard ratios (HR) alongside the corresponding 95% confidence interval (95% CI). The threshold for statistical significance was set at the level of P ≤ 0.05 a-priori. Results 205 patients with malignant small bowel obstruction presented to emergency surgery services during the study period. Of these patients, 50 had obstruction due to right sided colon cancer, 143 due to disseminated intraabdominal malignancy, 10 had primary tumours of the small bowel and 2 patients had gastrointestinal stromal tumours. In total 100 out of 205 patients underwent a surgical intervention for obstruction. 30-day in-hospital mortality rate was 11.3% for those with primary tumours and 19.6% for those with disseminated malignancy. Severe risk of malnutrition was an independent predictor for poor mortality in this cohort (adjusted HR 16.18, 95% CI 1.86 to 140.84, p = 0.012). Patients with right-sided colon cancer had high rates of morbidity. Conclusions Mortality rates were high in patients with disseminated malignancy and in those with right sided colon cancer. Further research should identify optimal management strategy to reduce morbidity for these patient groups

Charge-transporting and electroluminescent liquid crystals for organic light-emitting diodes

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Synthesis of dimethyl fluorene-9,9-diacetate

In this work, the synthesis and structural characterization of novel dimethyl fluorene-9,9-diacetate in a 4-step reaction pathway, starting from commercially available fluorene is reported. We envisaged this reagent to be useful in the field of organic semiconductor research.Link_to_subscribed_fulltex

Optical properties and photo-oxidation of tetraphenylethene-based fluorophores

We report the optical properties of tetraphenylethene (TPE) and other TPE derivatives functionalised with an octyl group (TPE-OCT) and polyethyleneglycol group (TPE-PEG) in the side chain. We compared TPE-OCT and TPE-PEG with TPE in both organic solvents and under aqueous conditions. All materials exhibit aggregation-induced emission, however, uncommonly, TPE-PEG seems to aggregate in aqueous solution with enhanced photoluminescence quantum efficiency (PLQE) relative to that in organic solvents. All three materials can be photo-oxidised in solution to their diphenylphenanthrene derivative by irradiation with UV light (at both ≈1 and ≈5 mW cm-2), with a subsequent enhancement in PL efficiency. The electron-donating ether group increases the rate of oxidation relative to bare TPE and also photo-oxidation was shown to be solvent and concentration dependent. Finally, photo-oxidation was also demonstrated in the aggregate state. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.Link_to_subscribed_fulltex

Charge-transport in crystalline organic semiconductors with liquid crystalline order

We report the design and synthesis of a liquid crystalline material exhibiting highly ordered smectic phases and high charge carrier-mobility; by a process known as "paramorphosis" highly ordered smectic phases can be transferred to the amorphous crystalline state on crystallisation without the formation of significant crystal grain boundaries and deep traps. © The Royal Society of Chemistry 2005.Link_to_subscribed_fulltex

Spiropyran-based molecular photoswitches

Spiropyran is one of the classic photochromic compounds, which undergoes photoisomerization under ultraviolet exposure with its structure transformed from a non-polar, closed and colorless spiro-form to a highly polar, open and colorful cyanine-form with extended π-electron delocalization. This has encourged researchers to employ this material with unique photochemical and photophysical properties as a molecular photoswitch in the field of optoelectronic devices, chemical biosensing, controlled release drug delivery and so on. In this review, noticeable designs, synthesis, properties of some spiropyran derivatives and their applications in relative fields are summarized. Finally, as a promising fluorescent probe, the future developing prospects in bioimaging are discussed and highlighted. © 2013 Chinese Chemical Society & SIOC, CAS.Link_to_subscribed_fulltex

Triplets in extended nematic liquid crystals and polarons in their blends

Photoinduced absorption shows that triplets are the primary photoexcited species in a series of conjugated liquid crystals containing thiophene and fluorene groups. We find that the triplet generation rate can be varied substantially by molecular design. The introduction of extra thiophene groups into the elongated molecules changes the intersystem crossing rate by over two orders of magnitude, while modifying the singlet and triplet energies by only small amounts. This result is attributed to the high spin-orbit coupling constant of sulfur: An increase in the number of sulfur atoms increases the spin-orbit coupling between the singlet and triplet states. These results are relevant to the design of organic light emitting diodes, lasers, and other devices where triplet formation has a major impact on device performance. The molecules are shown to act as effective electron donors when blended with a perylene molecule which acts as an electron acceptor. The electron transfer rate is faster than the singlet lifetime so that the blend shows the efficient charge separation required for a photovoltaic device. © 2007 American Institute of Physics.Link_to_subscribed_fulltex

Molecular photoswitches for super-resolution optical imaging

We report a series of fluorescence molecular switches including spiropyrans (SPs), dithienylethenes (DTEs) and hexaarylbiimidazoles (HABIs) and investigate their optical properties such as photochromism and photoswitchable aggregation-induced emission (condensed-state). © OSA 2013.Link_to_subscribed_fulltex

Distributed bilayer photovoltaics based on nematic liquid crystal polymer networks

We discuss a liquid crystal composite approach to provide a distributed interface to vertically separate electron-donating and electron-accepting films in an organic photovoltaic device. Two different methods are used to prepare a nematic liquid crystal polymer network with a porous surface and electron-donating properties. This is infilled with an electron-accepting organic semiconductor to form a bilayer device. The interface is diffuse rather than localized so that more photogenerated excitons can reach it to generate charge before they recombine. Photoinduced absorption of a blend of the donor and acceptor materials confirms that excitons dissociate at the heterointerface. The spatial features of the diffuse interface are examined by Fourier analysis of topographic images. We find a correlation between the in-plane spatial frequencies of the interface and photovoltaic device performance. The device performance is investigated as a function of input irradiance. Any charge combination is monomolecular rather than bimolecular, and the monochromatic power conversion efficiency varies between 0.8% and 0.3% with input irradiance. Equivalent circuit analysis shows that this is limited by a high series resistance, a blocking contact, and nonoptimized spatial features of the porous interface. © 2007 American Chemical Society.Link_to_subscribed_fulltex