Design of singlet fission chromophores by the introduction of N-oxyl fragments.

Singlet fission is a highly desired process in organic photovoltaic devices. It splits one singlet exciton into two triplet excitons and enhances the power-conversion efficiency. However, the exploitation of this process in photovoltaic devices is plagued by the small number of singlet fission chromophores. In this work, we designed a series of singlet fission chromophores by introducing N-oxyl fragments into anthracene. The diradical character brought by the N-oxyl fragments and the structural reorganizations in response to excitation to the lowest triplet state allow some of the investigated molecules to satisfy the thermodynamic energy criteria for singlet fission chromophores.

The Emerging Role of the RNA-Binding Protein SFPQ in Neuronal Function and Neurodegeneration.

RNA-binding proteins (RBPs) are a class of proteins known for their diverse roles in RNA biogenesis, from regulating transcriptional processes in the nucleus to facilitating translation in the cytoplasm. With higher demand for RNA metabolism in the nervous system, RBP misregulation has been linked to a wide range of neurological and neurodegenerative diseases. One of the emerging RBPs implicated in neuronal function and neurodegeneration is splicing factor proline- and glutamine-rich (SFPQ). SFPQ is a ubiquitous and abundant RBP that plays multiple regulatory roles in the nucleus such as paraspeckle formation, DNA damage repair, and various transcriptional regulation processes. An increasing number of studies have demonstrated the nuclear and also cytoplasmic roles of SFPQ in neurons, particularly in post-transcriptional regulation and RNA granule formation. Not surprisingly, the misregulation of SFPQ has been linked to pathological features shown by other neurodegenerative disease-associated RBPs such as aberrant RNA splicing, cytoplasmic mislocalization, and aggregation. In this review, we discuss recent findings on the roles of SFPQ with a particular focus on those in neuronal development and homeostasis as well as its implications in neurodegenerative diseases.

[Issues and implementation of postoperative radiotherapy after flap reconstructive surgery in head and neck cancers]. / Enjeux et mise en œuvre de radiothérapie postopératoire après chirurgie reconstructrice avec lambeau dans les cancers de la tête et du cou.

The management of head and neck cancers is multidisciplinary, often relying on the use of combined treatments to maximize the chances of cure. Combined treatments are however also responsible for cumulative side effects. The aim of reconstructive surgery with a flap is to restore a function lost with the loss of substance from the tumor resection. However, changes in reconstructive surgery have impact of postoperative radiotherapy planning. The optimization of imaging protocols for radiotherapy planning should make it possible to identify postoperative changes and to distinguish flaps from surrounding native tissues to delineate the flaps and document the spontaneous evolution of these flaps or dose-effect relationships in case of radiotherapy. Such changes include atrophy, fibrosis of soft tissue flaps and osteoradionecrosis of bone flaps. Radiotherapy optimization also involves standardization of the definition of target volumes in situations where a flap is present, a situation that is increasingly common in routine care. This evolution of practice, beyond the essential multidisciplinary consultation meetings defining treatment indications, requires a close radio surgical collaboration with respect to technical aspects of the two disciplines. Doing so, anticipation of relapse and toxicity profiles could possibly lead to propose strategies for personalized de-escalation of multimodal treatments through interdisciplinary trials.

Donor site morbidity of free ulnar forearm flap.

BACKGROUND: The purpose of this study was to evaluate the donor site morbidity of the free ulnar forearm flap (UFF). METHODS: Consecutive patients undergoing free UFF between 1982 and 2009 were retrospectively reviewed. In addition, detailed assessment of hand function and donor site cosmesis was performed in the most recent 50 patients followed up for at least 12 months. RESULTS: In all, 62 of the 242 free UFF donor sites (26%) were closed directly and the remainder required split thickness skin grafting. Donor site complications included total (n = 1) and partial (n = 17) skin graft loss and persistent hypertrophic scarring (n = 4). There was minimal incidence of cold intolerance, parasthesia, and pain; no reduction in joint mobility, grip and pinch strength, and sensory dysfunction, with excellent donor site cosmesis. CONCLUSIONS: UFF has several advantages, including the possibility of direct closure of the donor defect, and reduced morbidity and excellent donor site cosmesis.

Periaortic hematoma on abdominal computed tomographic scanning as an indicator of thoracic aortic rupture in blunt trauma.

BACKGROUND: In our institution, we have noted an association between periaortic hematomas (PH) present on abdominal computed tomographic (CT) scans and patients with thoracic aortic rupture (TAR) in blunt trauma. This 5-year retrospective study determined the sensitivity and specificity of PH and left hemothorax seen on abdominal CT scan as an indicator of TAR. METHODS: The trauma registry and records identified 54 blunt trauma patients who had a CT scan of the abdomen and an arch aortogram. Fourteen patients with TAR and 40 patients without TAR were selected for analysis. A digital photograph of an upper cut of the abdominal CT scan for each patient was examined by radiology staff for the presence or absence of PH and left hemothorax. RESULTS: The sensitivity, specificity, positive predictive value, and negative predictive value of PH as a predictor of TAR were 88%, 99%, 97%, and 96%, respectively. CONCLUSION: The finding of PH on CT scan of the abdomen in blunt trauma patients should alert the clinician to the high likelihood of thoracic aortic injury.