Charge injection across a polymeric heterojunction

The charge injection across a polymeric heterojunction of a poly-p-phenylene vinylene derivative (injecting layer) and poly (9,9-dioctylfluorene) (accepting layer) is investigated. The electric field in the accepting layer is obtained after correcting the applied voltage for the voltage drop across the injecting layer due to the buildup of space charge. At high electric fields, the current across the polymeric heterojunction exhibits only a weak dependence on the field due to the absence of image force effects, in agreement with model predictions. The strong dependence at low fields can be explained by taking the increase of the Fermi level into account, which effectively modifies the barrier for charge carriers waiting for a jump across the heterojunction

Велес – повелитель мертвих

In providing advice on herd health, veterinarians need to be aware of farmers' goals and priorities. To determine the level of awareness, 29 veterinarians from 15 practices completed questionnaires during visits to dairy farms within the scope of veterinary herd health management (VHHM) programmes. The farmers (n = 30) were asked to complete a questionnaire and their discussions with the veterinarian were recorded using a voice recorder. Herd performance goals were set by the farmer and veterinarian in 24% of cases. Veterinarians who did not set goals indicated that they and the farmer 'intuitively knew' what each wanted to achieve, and that the setting of performance goals was considered 'too formal'. Veterinarians often could not identify a farmer's main goal, and typically found milk production and nutrition significantly more important (P <0.01, and P <0.02, respectively), and fertility significantly less important (P <0.01) than the farmers. During on-farm conversations, veterinarians did not actively seek to identify farmers' goals or problems, suggest a co-operative strategy or summarise any advice given. The findings of this survey suggest that veterinarians need to focus more on goal setting, since awareness of goals and priorities is important for both communication and compliance with advice given. The needs of farmers with respect to herd health should also be more actively sought by veterinarians as the findings indicate that most farmers do not readily volunteer such information. (C) 2013 Published by Elsevier Ltd

TRPV1: A Target for Next Generation Analgesics

Transient Receptor Potential Vanilloid 1 (TRPV1) is a Ca2+ permeant non-selective cation channel expressed in a subpopulation of primary afferent neurons. TRPV1 is activated by physical and chemical stimuli. It is critical for the detection of nociceptive and thermal inflammatory pain as revealed by the deletion of the TRPV1 gene. TRPV1 is distributed in the peripheral and central terminals of the sensory neurons and plays a role in initiating action potentials at the nerve terminals and modulating neurotransmitter release at the first sensory synapse, respectively. Distribution of TRPV1 in the nerve terminals innervating blood vessels and in parts of the CNS that are not subjected to temperature range that is required to activate TRPV1 suggests a role beyond a noxious thermal sensor. Presently, TRPV1 is being considered as a target for analgesics through evaluation of different antagonists. Here, we will discuss the distribution and the functions of TRPV1, potential use of its agonists and antagonists as analgesics and highlight the functions that are not related to nociceptive transmission that might lead to adverse effects

Charge transport and trapping in Cs-doped poly(dialkoxy-p-phenylene vinylene) light-emitting diodes

Al/Cs/MDMO-PPV/ITO (where MDMO-PPV stands for poly[2-methoxy-5-(3'-7'-dimethyloctyloxy)-1,4phenylene vinylene] and ITO is indium tin oxide) light-emitting diode (LED) structures, made by physical vapor deposition of Cs on the emissive polymer layer, have been characterized by electroluminescence, current-voltage, and admittance spectroscopy. Deposition of Cs is found to improve the balance between electron and hole currents, enhancing the external electroluminescence efficiency from 0.01 cd A-1 for the bare Al cathode to a maximum of 1.3 cd A-1 for a Cs coverage of only 1.5×1014 atoms/cm2. By combining I-V and admittance spectra with model calculations, in which Cs diffusion profiles are explicitly taken into account, this effect could be attributed to a potential drop at the cathode interface due to a Cs-induced electron donor level 0.61 eV below the lowest unoccupied molecular orbital. In addition, the admittance spectra in the hole-dominated regime are shown to result from space-charge-limited conduction combined with charge relaxation in trap levels. This description allows us to directly determine the carrier mobility, even in the presence of traps. In contrast to recent literature, we demonstrate that there is no need to include dispersive transport in the description of the carrier mobility to explain the excess capacitance that is typically observed in admittance spectra of p-conjugated materials

Dietary intakes of individual flavanols and flavonols are inversely associated with incident type 2 diabetes in European populations.

Dietary flavanols and flavonols, flavonoid subclasses, have been recently associated with a lower risk of type 2 diabetes (T2D) in Europe. Even within the same subclass, flavonoids may differ considerably in bioavailability and bioactivity. We aimed to examine the association between individual flavanol and flavonol intakes and risk of developing T2D across European countries. The European Prospective Investigation into Cancer and Nutrition (EPIC)-InterAct case-cohort study was conducted in 8 European countries across 26 study centers with 340,234 participants contributing 3.99 million person-years of follow-up, among whom 12,403 incident T2D cases were ascertained and a center-stratified subcohort of 16,154 individuals was defined. We estimated flavonoid intake at baseline from validated dietary questionnaires using a database developed from Phenol-Explorer and USDA databases. We used country-specific Prentice-weighted Cox regression models and random-effects meta-analysis methods to estimate HRs. Among the flavanol subclass, we observed significant inverse trends between intakes of all individual flavan-3-ol monomers and risk of T2D in multivariable models (all P-trend < 0.05). We also observed significant trends for the intakes of proanthocyanidin dimers (HR for the highest vs. the lowest quintile: 0.81; 95% CI: 0.71, 0.92; P-trend = 0.003) and trimers (HR: 0.91; 95% CI: 0.80, 1.04; P-trend = 0.07) but not for proanthocyanidins with a greater polymerization degree. Among the flavonol subclass, myricetin (HR: 0.77; 95% CI: 0.64, 0.93; P-trend = 0.001) was associated with a lower incidence of T2D. This large and heterogeneous European study showed inverse associations between all individual flavan-3-ol monomers, proanthocyanidins with a low polymerization degree, and the flavonol myricetin and incident T2D. These results suggest that individual flavonoids have different roles in the etiology of T2D.The EPIC-InterAct Study was supported by the European Union (Integrated Project LSHM-CT-2006-037197 in the Framework Programme 6 of the European Community). In addition, InterAct investigators acknowledge funding from the following agencies: R.Z.-R. was supported by a postdoctoral program Fondo de Investigación Sanitaria (FIS; no. CD09/00133) from the Spanish Ministry of Science; R.Z.-R. and C.A.G. were supported by the Health Research Fund (FIS) of the Spanish Ministry of Health (RTICC DR06/0020/0091); core support from the Medical Research Council (MRC) Epidemiology Unit is acknowledged for program MC_UU_12015/1 and MC_UU_12015/5; Y.T.v.d.S. was supported by NL Agency grant IGE05012 and an Incentive Grant from the Board of the UMC Utrecht (Netherlands); A.M.W.S. and D.L.v.d.A. were supported by the Dutch Ministry of Public Health, Welfare, and Sports, Netherlands Cancer Registry, LK Research Funds, Dutch Prevention Funds, Dutch ZON, World Cancer Research Fund, and Statistics Netherlands; T.J.K. and K.-T.K. were supported by Cancer Research UK; G.F., M.T., and F.P. were supported by Ligue contre le Cancer, Institut Gustave Roussy, Mutuelle Générale de l’Education Nationale, INSERM; G.M. was supported by Ministero della Salute Regione Toscana Progetto Integrato Oncologia–PIO; P.W.F. was supported by the Swedish Research Council, Novo Nordisk, the Swedish Heart Lung Foundation, and the Swedish Diabetes Association; L.B., K.O., N.R., and A.T. were supported by the Danish Cancer Society; V.K. and T.K. were supported by Deutsche Krebshilfe; A.M. was supported by Associazione Italiana per la Ricerca sul Cancro; M.L.R. was supported by the Asturias Regional Government; M.G., P.A., E.M.-M., and M.J.T. were supported by the Health Research Fund of the Spanish Ministry of Health, CIBER Epidemiology and Public Health (Spain); M.J.T. was supported by the Murcia Regional Government; and R.T. was supported by AIRE-ONLUS Ragusa, AVIS-Ragusa, the Sicilian Regional Government.This is the final published version distributed under a Creative Commons Attribution Licence, which can also be found on the publisher's website at: http://jn.nutrition.org/content/144/3/335.ful