3,810 research outputs found

    Triplet luminescent dinuclear-gold(I) complex-based light-emitting diodes with low turn-on voltage

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    The electroluminescence (EL) from a dinuclear-gold(I)-chlorate compound containing bridging phosphine ligands [Au 2(dppm)Cl 2] as emitting layer is reported. Devices with a structure Al/Au 2(dppm)Cl 2/indium-tin-oxide demonstrated a uniform emission under the driving voltage below 1 V. The EL emission was from triplet excited state and the emission color of the device was found to depend on the deposition rate of Au 2(dppm)Cl 2, which can be explained as the different aggregation forms of the stacking compound in the deposition process. © 1999 American Institute of Physics.published_or_final_versio

    Skin necrosis in smoking patients receiving partial breast irradiation: two case reports

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    Partial breast irradiation has become an increasingly popular mode of treatment after excisional biopsy to treat early stage invasive breast cancer. Its main advantage is that treatment can be delivered in five days rather than 30, as is standard for whole breast irradiation. Early reports suggest good to excellent cosmesis in the vast majority of subjects. Herein we report two cases of skin necrosis in women with Stage 1 breast cancer who smoked before and after partial breast irradiation

    Permeation of Herbicidal Dichlobenil From a Casoron Formulation Through Nitrile Gloves

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    The aim of this study was to measure permeation of the herbicide dichlobenil in Casoron 4G through disposable and chemically protective nitrile gloves using an American Society for Testing and Materials-type permeation cell and a closed-loop system employing two different solvents (hexane and water) and two different challenge situations (aqueous emulsion and solid formulation). Capillary gas chromatography–mass spectrometry was used for quantification purposes. The chemically protective glove did not allow any permeation up to 8 h for the solid-formulation and water-collection challenges, but permeation was detected in all other challenges. The disposable glove allowed the most permeation, and the solid-formulation challenge with water collection necessitated that a dichlobenil equivalent be calculated because of the presence of its hydrolysis degradation product 2,6-dichlorobenzamide. Permeation from the solid formulation was detectable by hexane collection for both the disposable and chemically protective gloves and by water collection for the disposable glove. It was concluded that hexane-solvent collection was not valid for the disposable glove at 4 and 8 h of permeation in the solid Casoron challenge or for the aqueous emulsion challenge at 8 h relative to the water-collection solvent data. The hexane-solvent collection for the chemically protective glove was valid for the 8-h solid-formulation challenge but not for the 8-h aqueous-solution challenge. All water-solvent collections were valid; however, dichlobenil usually permeated the gloves

    The role of mentorship in protege performance

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    The role of mentorship on protege performance is a matter of importance to academic, business, and governmental organizations. While the benefits of mentorship for proteges, mentors and their organizations are apparent, the extent to which proteges mimic their mentors' career choices and acquire their mentorship skills is unclear. Here, we investigate one aspect of mentor emulation by studying mentorship fecundity---the number of proteges a mentor trains---with data from the Mathematics Genealogy Project, which tracks the mentorship record of thousands of mathematicians over several centuries. We demonstrate that fecundity among academic mathematicians is correlated with other measures of academic success. We also find that the average fecundity of mentors remains stable over 60 years of recorded mentorship. We further uncover three significant correlations in mentorship fecundity. First, mentors with small mentorship fecundity train proteges that go on to have a 37% larger than expected mentorship fecundity. Second, in the first third of their career, mentors with large fecundity train proteges that go on to have a 29% larger than expected fecundity. Finally, in the last third of their career, mentors with large fecundity train proteges that go on to have a 31% smaller than expected fecundity.Comment: 23 pages double-spaced, 4 figure

    Prognosis of Sentinel Node Staged Patients with Primary Cutaneous Melanoma

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    Background: This study investigated survival probabilities and prognostic factors in sentinel lymph node biopsy (SLNB) staged patients with cutaneous melanoma (CM) with the aim of defining subgroups of patients who are at higher risk for recurrences and who should be considered for adjuvant clinical trials.\ud \ud Methods: Patients with primary CM who underwent SLNB in the Department of Dermatology, University of Tuebingen, Germany, between 1996 and 2009 were included into this study. Survival probabilities and prognostic factors were evaluated by Kaplan-Meier and multivariate Cox proportional hazard models.\ud \ud Results: 1909 SLNB staged patients were evaluated. Median follow-up time was 44 months. Median tumor thickness was 1.8 mm, ulceration was present in 31.8% of cases. The 5-year Overall Survival (OS) was 90.3% in SLNB negative patients (IB 96.2%, IIA 87.0%, IIB 78.1%, IIC 72.6%). Patients with micrometastases (stage IIIA/B) had a 5-year OS rate of 70.9% which was clearly less favorable than for stages I–II. Multivariate analysis revealed tumor thickness, ulceration, body site, histopathologic subtype and SLNB status as independent significant prognostic factors.\ud \ud Conclusion: Survival rates of patients with primary CM in stages I–II were shown to be much more favorable than previously reported from non sentinel node staged collectives. For future clinical trials, sample size calculations should be adapted using survival probabilities based on sentinel node staging

    Contrasting prefrontal cortex contributions to episodic memory dysfunction in behavioural variant frontotemporal dementia and alzheimer's disease

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    Recent evidence has questioned the integrity of episodic memory in behavioural variant frontotemporal dementia (bvFTD), where recall performance is impaired to the same extent as in Alzheimer's disease (AD). While these deficits appear to be mediated by divergent patterns of brain atrophy, there is evidence to suggest that certain prefrontal regions are implicated across both patient groups. In this study we sought to further elucidate the dorsolateral (DLPFC) and ventromedial (VMPFC) prefrontal contributions to episodic memory impairment in bvFTD and AD. Performance on episodic memory tasks and neuropsychological measures typically tapping into either DLPFC or VMPFC functions was assessed in 22 bvFTD, 32 AD patients and 35 age- and education-matched controls. Behaviourally, patient groups did not differ on measures of episodic memory recall or DLPFC-mediated executive functions. BvFTD patients were significantly more impaired on measures of VMPFC-mediated executive functions. Composite measures of the recall, DLPFC and VMPFC task scores were covaried against the T1 MRI scans of all participants to identify regions of atrophy correlating with performance on these tasks. Imaging analysis showed that impaired recall performance is associated with divergent patterns of PFC atrophy in bvFTD and AD. Whereas in bvFTD, PFC atrophy covariates for recall encompassed both DLPFC and VMPFC regions, only the DLPFC was implicated in AD. Our results suggest that episodic memory deficits in bvFTD and AD are underpinned by divergent prefrontal mechanisms. Moreover, we argue that these differences are not adequately captured by existing neuropsychological measures

    Environmental DNA analysis as an emerging non-destructive method for plant biodiversity monitoring: a review

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    Environmental DNA (eDNA) analysis has recently transformed and modernized biodiversity monitoring. The accurate detection, and to some extent quantification, of organisms (individuals/populations/communities) in environmental samples is galvanizing eDNA as a successful cost and time-efficient biomonitoring technique. Currently, eDNA’s application to plants remains more limited in implementation and scope compared to animals and microorganisms. Thus, this review evaluates the development of eDNA-based methods for (vascular) plants, comparing its performance and power of detection with that of traditional methods, to critically evaluate and advise best practices needed for innovating plant biomonitoring. Recent advancements, standardization, and field applications of eDNA-based methods have provided enough scope to utilize it in conservation biology for numerous organisms. eDNA also has considerable potential for plants, where successful detection of invasive, endangered and rare species, and community-level interpretations have provided proof-of-concept. Monitoring methods using eDNA were found to be equal or more effective than traditional methods, however species detection increased when both the methods were coupled. Additionally, eDNA methods were found to be effective in studying species interactions, community dynamics, and even effects of anthropogenic pressure. Currently, elimination of potential obstacles (e.g., lack of relevant DNA reference libraries for plants) and the development of user-friendly protocols would greatly contribute to comprehensive eDNA-based plant monitoring programs. This is particularly needed in the data-depauperate tropics and for some less-concern plant groups. We further advocate it may be valuable to couple traditional methods with eDNA approaches, as the former is often cheaper and methodologically more straightforward, while the latter offers a non-destructive approach with the ability to identify plants in situations where morphological identification is difficult or impossible. Furthermore, in order to make a global platform for eDNA, governmental and academic-industrial collaborations are essential to make eDNA surveys a broadly adopted and implemented, rapid, cost-effective, and non-invasive plant monitoring approach

    Deriving a mutation index of carcinogenicity using protein structure and protein interfaces

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    With the advent of Next Generation Sequencing the identification of mutations in the genomes of healthy and diseased tissues has become commonplace. While much progress has been made to elucidate the aetiology of disease processes in cancer, the contributions to disease that many individual mutations make remain to be characterised and their downstream consequences on cancer phenotypes remain to be understood. Missense mutations commonly occur in cancers and their consequences remain challenging to predict. However, this knowledge is becoming more vital, for both assessing disease progression and for stratifying drug treatment regimes. Coupled with structural data, comprehensive genomic databases of mutations such as the 1000 Genomes project and COSMIC give an opportunity to investigate general principles of how cancer mutations disrupt proteins and their interactions at the molecular and network level. We describe a comprehensive comparison of cancer and neutral missense mutations; by combining features derived from structural and interface properties we have developed a carcinogenicity predictor, InCa (Index of Carcinogenicity). Upon comparison with other methods, we observe that InCa can predict mutations that might not be detected by other methods. We also discuss general limitations shared by all predictors that attempt to predict driver mutations and discuss how this could impact high-throughput predictions. A web interface to a server implementation is publicly available at http://inca.icr.ac.uk/

    Recent advances in radiotherapy

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    Radiation therapy has come a long way from treatment planning based on orthogonal radiographs with large margins around tumours. Advances in imaging and radiation planning software have led to three-dimensional conformal radiotherapy and, further, to intensity modulated radiotherapy (IMRT). IMRT permits sparing of normal tissues and hence dose-escalation to tumours. IMRT is the current standard in treatment of head and prostate cancer and is being investigated in other tumour sites. Exquisitely sculpted dose distributions (increased geographical miss) with IMRT, plus tumour motion and anatomical changes during radiotherapy make image guided radiotherapy an essential part of modern radiation delivery. Various hardware and software tools are under investigation for optimal IGRT
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