Customizing the Polarity of Single-Walled Carbon-Nanotube Field-Effect Transistors Using Solution-Based Additives

Polarity control in semiconducting single-walled carbon-nanotube field-effect transistors (s-SWNT FETs) is important to promote their application in logic devices. The methods to turn the intrinsically ambipolar s-SWNT FETs into unipolar devices that have been proposed until now require extra fabrication steps that make preparation longer and more complex. It is demonstrated that by starting from a highly purified ink of semiconducting single-walled carbon nanotubes sorted by a conjugated polymer, and mixing them with additives, it is possible to achieve unipolar charge transport. The three additives used are benzyl viologen (BV), 4-(2,3-dihydro-1,3-dimethyl-1H-benzimidazol-2-yl)-N,N-dimethylbenzenamine (N-DMBI), which give rise to n-type field-effect transistors, and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F-4-TCNQ) which gives rise to p-type transistors. BV and N-DMBI transform the s-SWNTs transistors from ambipolar with mobility of the order of 0.7 cm(2) V-1 s(-1) to n-type with mobility up to 5 cm(2) V-1 s(-1). F-4-TCNQ transform the ambipolar transistors in p-type with mobility up to 16 cm(2) V-1 s(-1)

Current Practice of Heart Donor Evaluation in Germany: Multivariable Risk Factor Analysis Confirms Practicability of Guidelines

Background. Organ shortage has liberalised the acceptance criteria of grafts for heart transplantation, but which donor characteristics ultimately influence the decision to perform transplantation? For the first time this was evaluated using real-time donor data from the German organ procurement organization (DSO). Observed associations are discussed with regard to international recommendations and guidelines. Methods. 5291 German donors (2006–2010) were formally eligible for heart donation. In logistic regression models 160 donor parameters were evaluated to assess their influence on using grafts for transplantation (random split of cases: 2/3 study sample, 1/3 validation sample). Results. Successful procurement was determined by low donor age (OR 0.87 per year; 95% CI [0.85–0.89], P<0.0001), large donor height (OR 1.04 per cm; 95% CI [1.02–1.06], P<0.0001), exclusion of impaired left ventricular function or wall motion (OR 0.01; 95% CI [0.002–0.036], P<0.0001), arrhythmia (OR 0.05; 95% CI [0.009–0.260], P=0.0004), and of severe coronary artery disease (OR 0.003; 95% CI [<0.001–0.01], P<0.0001). Donor characteristics differed between cases where the procedure was aborted without and with allocation initiated via Eurotransplant

A Hardware/Software Stack for Heterogeneous Systems

Plenty of novel emerging technologies are being proposed and evaluated today, mostly at the device and circuit levels. It is unclear what the impact of different new technologies at the system level will be. What is clear, however, is that new technologies will make their way into systems and will increase the already high complexity of heterogeneous parallel computing platforms, making it ever so difficult to program them. This paper discusses a programming stack for heterogeneous systems that combines and adapts well-understood principles from different areas, including capability-based operating systems, adaptive application runtimes, dataflow programming models, and model checking. We argue why we think that these principles built into the stack and the interfaces among the layers will also be applicable to future systems that integrate heterogeneous technologies. The programming stack is evaluated on a tiled heterogeneous multicore

Stability of oxylipins during plasma generation and long-term storage

International audienceOxidized unsaturated fatty acids - i.e. eicosanoids and other oxylipins - are lipid mediators involved in the regulation of numerous physiological functions such as inflammation, blood coagulation, vascular tone and endothelial permeability. They have raised strong interest in clinical lipidomics in order to understand their role in health and diseases and their use as biomarkers. However, before the clinical translation, it is crucial to validate the analytical reliability of oxylipins. This notably requires to assess the putative artificial formation or degradation of oxylipins by (unsuitable) blood handling during plasma generation, storage and sample preparation. Using a liquid chromatography-mass spectrometry method covering 133 oxylipins we comprehensively analyzed the total (free + esterified) oxylipin profile in plasma and investigated the influence of i) addition of additives during sample preparation, ii) different storage times and temperatures during the transitory stage of plasma generation and iii) long-term storage of plasma samples at -80 degrees C. Addition of radical scavenger butylated hydroxytoluene reduced the apparent concentrations of hydroxy-PUFA and thus should be added to the samples at the beginning of sample preparation. The concentrations of all oxylipin classes remained stable (within analytical variance of 20%) during the transitory stage of plasma generation up to 24 h at 4 degrees C or 4 h at 20 degrees C before centrifugation of EDTA-whole blood and up to 5 days at - 20 degrees C after plasma separation. The variations in oxylipin concentrations did not correlate with storage time, storage temperature or stage of plasma generation. A significant increase of potentially lipoxygenase derived hydroxy-PUFA compared to immediate processing was only detected when samples were stored for longer times before centrifugation, plasma separation as well as freezing of plasma revealing residual enzymatic activity. Autoxidative rather than enzymatic processes led to a slightly increased concentration of 9-HETE when plasma samples were stored at - 80 degrees C for 15 months. Overall, we demonstrate that total plasma oxylipins are robust regarding delays during plasma generation and long-term storage at -80 degrees C supporting the application of oxylipin profiling in clinical research