399 research outputs found
The effect of applied magnetic field on photocurrent generation in poly-3-hexylthiophene:[6,6]-phenyl C61-butyric acid methyl ester photovoltaic devices
This is the author’s version of a work that was accepted for publication in Journal of Physics: Condensed Matter http://dx.doi.org/10.1088/0953-8984/20/45/45220
Recombination Dynamics as a Key Determinant of Open Circuit Voltage in Organic Bulk Heterojunction Solar Cells: A Comparison of Four Different Donor Polymers
NuSTAR observations of Mrk 766: Distinguishing reflection from absorption
We present two new NuSTAR observations of the narrow line Seyfert 1 (NLS1) galaxy Mrk 766 and give constraints on the two scenarios previously proposed to explain its spectrum and that of other NLS1s: relativistic reflection and partial covering. The NuSTAR spectra show a strong hard (> 15 keV) X-ray excess, while simultaneous soft X-ray coverage of one of the observations provided by XMM-Newton constrains the ionised absorption in the source. The pure reflection model requires a black hole of high spin (a > 0.92) viewed at a moderate inclination (i = 46 +1 −4 ). The pure partial covering model requires extreme parameters: the cut-off of the primary continuum is very low (22 +7 −5 keV) in one observation and the intrinsic X-ray emission must provide a large fraction (75%) of the bolometric luminosity. Allowing a hybrid model with both partial covering and reflection provides more reasonable absorption parameters and relaxes the constraints on reflection parameters. The fractional variability reduces around the iron K band and at high energies including the Compton hump, suggesting that the reflected emission is less variable than the continuum
The corona of the broad-line radio galaxy 3C 390.3
We present the results from a joint Suzaku/NuSTAR broad-band spectral
analysis of 3C 390.3. The high quality data enables us to clearly separate the
primary continuum from the reprocessed components allowing us to detect a high
energy spectral cut-off ( keV), and to place
constraints on the Comptonization parameters of the primary continuum for the
first time. The hard over soft compactness is 69 and the optical
depth 4.1, this leads to an electron temperature of
keV. Expanding our study of the Comptonization spectrum to the
optical/UV by studying the simultaneous Swift-UVOT data, we find indications
that the compactness of the corona allows only a small fraction of the total
UV/optical flux to be Comptonized. Our analysis of the reprocessed emission
show that 3C 390.3 only has a small amount of reflection (R~0.3), and of that
the vast majority is from distant neutral matter. However we also discover a
soft X-ray excess in the source, which can be described by a weak ionized
reflection component from the inner parts of the accretion disk. In addition to
the backscattered emission, we also detect the highly ionized iron emission
lines Fe XXV and Fe XXVI
Enzymatic capacities of metabolic fuel use in cuttlefish (Sepia officinalis) and responses to food deprivation: insight into the metabolic organization and starvation survival strategy of cephalopods
Food limitation is a common challenge for animals. Cephalopods are sensitive to starvation because of high metabolic rates and growth rates related to their "live fast, die young" life history. We investigated how enzymatic capacities of key metabolic pathways are modulated during starvation in the common cuttlefish (Sepia officinalis) to gain insight into the metabolic organization of cephalopods and their strategies for coping with food limitation. In particular, lipids have traditionally been considered unimportant fuels in cephalopods, yet, puzzlingly, many species (including cuttlefish) mobilize the lipid stores in their digestive gland during starvation. Using a comprehensive multi-tissue assay of enzymatic capacities for energy metabolism, we show that, during long-term starvation (12 days), glycolytic capacity for glucose use is decreased in cuttlefish tissues, while capacities for use of lipid-based fuels (fatty acids and ketone bodies) and amino acid fuels are retained or increased. Specifically, the capacity to use the ketone body acetoacetate as fuel is widespread across tissues and gill has a previously unrecognized capacity for fatty acid catabolism, albeit at low rates. The capacity for de novo glucose synthesis (gluconeogenesis), important for glucose homeostasis, likely is restricted to the digestive gland, contrary to previous reports of widespread gluconeogenesis among cephalopod tissues. Short-term starvation (3-5 days) had few effects on enzymatic capacities. Similar to vertebrates, lipid-based fuels, putatively mobilized from fat stores in the digestive gland, appear to be important energy sources for cephalopods, especially during starvation when glycolytic capacity is decreased perhaps to conserve available glucose
Heritage branding orientation: The case of Ach. Brito and the dynamics between corporate and product heritage brands
The notion of heritage branding orientation is introduced and explicated. Heritage branding orientation is designated as embracing both product and corporate brands and differs from corporate heritage brand orientation which has an explicit corporate focus. Empirical insights are drawn from an in-depth and longitudinal case study of Ach. Brito, a celebrated Portuguese manufacturer of soaps and toiletries. This study shows how, by the pursuance of a strategy derived from a heritage branding orientation Ach. Brito – after a prolonged period of decline – achieved a dramatic strategic turnaround. The findings reveal how institutional heritage can be a strategic resource via its adoption and activation at both the product and corporate levels. Moreover, the study showed how the bi-lateral interplay between product and corporate brand levels can be mutually reinforcing. In instrumental terms, the study shows how heritage can be activated and articulated in different ways. For instance, it can re-position both product and/or corporate brands; it can be meaningfully informed by product brand heritage and shape corporate heritage; and can be of strategic importance to both medium-sized and small enterprises
Morphinofobia: the situation among the general population and health care professionals in North-Eastern Portugal
<p>Abstract</p> <p>Background</p> <p>Morphinofobia among the general population (GP) and among health care professionals (HP) is not without danger for the patients: it may lead to the inappropriate management of debilitating pain. The aim of our study was to explore among GP and HP the representation and attitudes concerning the use of morphine in health care.</p> <p>Methods</p> <p>A cross-sectional study was done among 412 HP (physicians and nurses) of the 4 hospitals and 10 community health centers of Beira Interior (Portugal)and among 193 persons of the GP randomly selected in public places. Opinions were collected through a translated self-administered questionnaire.</p> <p>Results</p> <p>A significant difference of opinion exists among GP and HP about the use of morphine. The word morphine first suggests drug to GP (36,2%) and analgesia to HP (32,9%.). The reasons for not using morphine most frequently cited are: for GP morphine use means advanced disease (56%), risk of addiction (50%), legal requirements (49,7%); for HP it means legal risks (56,3%) and adverse side effects of morphine such as somnolence - sedation (30,5%) The socio-demographic situation was correlated with the opinions about the use of morphine.</p> <p>Conclusions</p> <p>False beliefs about the use of morphine exist among the studied groups. There seems to be a need for developing information campaigns on pain management and the use of morphine targeting. Better training and more information of HP might also be needed.</p
Meta-analysis of genome-wide association studies from the CHARGE consortium identifies common variants associated with carotid intima media thickness and plaque
Carotid intima media thickness (cIMT) and plaque determined by ultrasonography are established measures of subclinical atherosclerosis that each predicts future cardiovascular disease events. We conducted a meta-analysis of genome-wide association data in 31,211 participants of European ancestry from nine large studies in the setting of the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium. We then sought additional evidence to support our findings among 11,273 individuals using data from seven additional studies. In the combined meta-analysis, we identified three genomic regions associated with common carotid intima media thickness and two different regions associated with the presence of carotid plaque (P < 5 × 10 -8). The associated SNPs mapped in or near genes related to cellular signaling, lipid metabolism and blood pressure homeostasis, and two of the regions were associated with coronary artery disease (P < 0.006) in the Coronary Artery Disease Genome-Wide Replication and Meta-Analysis (CARDIoGRAM) consortium. Our findings may provide new insight into pathways leading to subclinical atherosclerosis and subsequent cardiovascular events
Neurocognitive functioning in school-aged cystinosis patients
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89600.pdf (publisher's version ) (Closed access)INTRODUCTION: Cystinosis is an autosomal recessive disorder leading to intralysosomal cystine accumulation in various tissues. It causes renal Fanconi syndrome and end stage renal failure around the age of 10 years if not treated with cysteamine. Children with cystinosis seem to have a normal intelligence but frequently show learning difficulties. These problems may be due to specific neurocognitive deficits rather than impaired renal function. Whether cysteamine treatment can improve cognitive functioning of cystinosis patients is thus far unknown. We aim to analyze neurocognitive functioning of school-aged cystinosis patients treated with cysteamine in order to identify specific deficits that can lead to learning difficulties. PATIENTS AND METHODS: Fourteen Dutch and Belgian school-aged cystinosis patients were included. Glomerular filtration rate was estimated using the Schwartz formula. Children were tested for general intelligence, visual-motor integration, inhibition, interference, sustained attention, accuracy, planning, visual memory, processing speed, motor planning, fluency and speed, and behavioural and emotional functioning using standardized methods. RESULTS: Glomerular filtration rate ranged from 22 to 120 ml min(-1) 1.73 m(-2). Median full-scale intelligence was below the average of a normal population (87, range 60-132), with a discrepancy between verbal (median 95, range 60-125) and performance (median 87, range 65-130) intelligence. Over 50% of the patients scored poorly on visual-motor integration, sustained attention, visual memory, planning, or motor speed. The other tested areas showed no differences between patients' and normal values. CONCLUSION: Neurocognitive diagnostics are indicated in cystinosis patients. Early recognition of specific deficits and supervision from special education services might reduce learning difficulties and improve school careers.1 december 201
Mechanical cleaning of graphene using in situ electron microscopy
Avoiding and removing surface contamination is a crucial task when handling specimens in any scientific experiment. This is especially true for two-dimensional materials such as graphene, which are extraordinarily affected by contamination due to their large surface area. While many efforts have been made to reduce and remove contamination from such surfaces, the issue is far from resolved. Here we report on an in situ mechanical cleaning method that enables the site-specific removal of contamination from both sides of two dimensional membranes down to atomic-scale cleanliness. Further, mechanisms of re-contamination are discussed, finding surface-diffusion to be the major factor for contamination in electron microscopy. Finally the targeted, electron-beam assisted synthesis of a nanocrystalline graphene layer by supplying a precursor molecule to cleaned areas is demonstrated
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