Coupled opto-electronic simulation of organic bulk-heterojunction solar cells: parameter extraction and sensitivity analysis

A general problem arising in computer simulations is the number of material and device parameters, which have to be determined by dedicated experiments and simulation-based parameter extraction. In this study we analyze measurements of the short-circuit current dependence on the active layer thickness and current-voltage curves in poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM) based solar cells. We have identified a set of parameter values including dissociation parameters that describe the experimental data. The overall agreement of our model with experiment is good, however a discrepancy in the thickness dependence of the current-voltage curve questions the influence of the electric field in the dissociation process. In addition transient simulations are analyzed which show that a measurement of the turn-off photocurrent can be useful for estimating charge carrier mobilities.Comment: 10 pages, 12 figures, 2 tables, Accepted for publication in Journal of Applied Physic

Quels sont les bénéfices d'une immunisation passive postexpositionnelle contre la rougeole ? : Revue Cochrane pour le praticien

Question clinique : Une patiente de 43 ans connue pour un lupus érythémateux disséminé et une néphropathie lupique stable et traitée par hydroxychloroquine et mycophénolate mofétil vous rapporte avoir eu contact il y a quatre jours avec un enfant atteint de la rougeole. Elle ne présente aucun symptôme et son dernier bilan vaccinal montre un taux d'anticorps contre la rougeole non protecteur. La patiente devrait-elle recevoir une immunisation active ou passive contre la rougeole? Contexte En Suisse : la couverture vaccinale contre la rougeole n'est pas assez importante pour empêcher sa diffusion. L'immunisation passive avec des immunoglobulines est destinée aux personnes non immunes exposées à la rougeole, recommandée en Suisse aux personnes à haut risque. Cette revue visait à évaluer l'efficacité et l'innocuité de l'injection intramusculaire ou de la perfusion intraveineuse d'immunoglobulines pour prévenir la rougeole chez les personnes susceptibles avant l'apparition des symptômes

Est-il possible d'optimiser le traitement médicamenteux des patients âgés ?

Contexte: La polymédication, définie ici comme la prescription simultanée de M 4 médicaments, est fréquente chez les personnes de M 65 ans. Celle-ci peut s'accompagner d'une mauvaise adhérence aux traitements et provoquer des effets indésirables. Cette revue systématique a évalué l'efficacité des interventions visant à améliorer l'adéquation de la polymédication chez la personne âgée (M 65 ans) présentant deux maladies chroniques ou plus

Phimosis et corticostéroïdes topiques : une alternative au traitement chirurgical? : revue Cochrane pour le praticien

Question clinique: Une mère vous consulte avec son fils âgé de 6 ans, en bonne santé habituelle mais connu pour un phimosis. Il ne présente pas de troubles mictionnels, ni d'antécédents de balanite ou de paraphimosis. Sa mère est inquiète de voir le phimosis persister et vous demande s'il existe une alternative au traitement chirurgical. Contexte: Présent dès la naissance, le phimosis physiologique se résout spontanément dans la majorité des cas. Alors que 10% des garçons présentent un phimosis à l'âge de 3 ans, cette prévalence diminue à 6-8% à l'âge de 7 ans, pour atteindre 1% à l'âge de 16 ans. On parle de phimosis pathologique lorsque le prépuce présente des cicatrices fibreuses suite à des inflammations répétées ou des décalottages forcés. Cependant, la distinction clinique entre un phimosis pathologique et physiologique est difficile et le traitement chirurgical reste fréquent. Un traitement par corticostéroïdes topiques est utilisé depuis de nombreuses années pour son action anti-inflammatoire et immunosuppressive (diminution de la production de collagène). Pourtant, il n'existe pas de preuve quant à l'efficacité et la sécurité de ce traitement

No consistent association between processes-of-care and health-related quality of life among patients with diabetes : a missing link?

PURPOSE: Health-related quality of life (HRQoL) is considered a representative outcome in the evaluation of chronic disease management initiatives emphasizing patient-centered care. We evaluated the association between receipt of processes-of-care (PoC) for diabetes and HRQoL. METHODS: This cross-sectional study used self-reported data from non-institutionalized adults with diabetes in a Swiss canton. Outcomes were the physical/mental composites of the short form health survey 12 (SF-12) physical composite score, mental composite score (PCS, MCS) and the Audit of Diabetes-Dependent Quality of Life (ADDQoL). Main exposure variables were receipt of six PoC for diabetes in the past 12 months, and the Patient Assessment of Chronic Illness Care (PACIC) score. We performed linear regressions to examine the association between PoC, PACIC and the three composites of HRQoL. RESULTS: Mean age of the 519 patients was 64.5 years (SD 11.3); 60% were male, 87% reported type 2 or undetermined diabetes and 48% had diabetes for over 10 years. Mean HRQoL scores were SF-12 PCS: 43.4 (SD 10.5), SF-12 MCS: 47.0 (SD 11.2) and ADDQoL: -1.6 (SD 1.6). In adjusted models including all six PoC simultaneously, receipt of influenza vaccine was associated with lower ADDQoL (β=-0.4, p≤0.01) and foot examination was negatively associated with SF-12 PCS (β=-1.8, p≤0.05). There was no association or trend towards a negative association when these PoC were reported as combined measures. PACIC score was associated only with the SF-12 MCS (β=1.6, p≤0.05). CONCLUSIONS: PoC for diabetes did not show a consistent association with HRQoL in a cross-sectional analysis. This may represent an effect lag time between time of process received and health-related quality of life. Further research is needed to study this complex phenomenon

Enurésie nocturne : quel traitement efficace non pharmacologique recommander ?

L'énurésie nocturne est une affection commune qui touche jusqu'à 20% des enfants de 5 ans. Cette prévalence diminue ensuite rapidement pour atteindre 7% à l'âge de 7 ans et pas plus de 2% à l'âge adulte. Quoique bénigne, elle est souvent source de stigmatisation sociale et peut affecter à la fois l'estime de soi et les relations avec les pairs. Les interventions de type comportemental (ICS) sont fréquentes et constituent souvent le premier choix des parents et de l'enfant. Une controverse persiste toutefois quant à leur efficacité. Le but de la mise à jour de cette revue est d'évaluer l'efficacité d'interventions comportementales simples (ICS : restriction hydrique, lever, réveil, récompenses, exercices de rétention), entre elles et par rapport à d'autres traitements

Association between education and quality of diabetes care in Switzerland

PURPOSE: Low socioeconomic status is associated with higher prevalence of diabetes, worse outcomes, and worse quality of care. We explored the relationship between education, as a measure of socioeconomic status, and quality of care in the Swiss context. PATIENTS AND METHODS: Data were drawn from a population-based survey of 519 adults with diabetes during fall 2011 and summer 2012 in a canton of Switzerland. We assessed patients and diabetes characteristics. Eleven indicators of quality of care were considered (six of process and five of outcomes of care). After bivariate analyses, regression analyses adjusted for age, sex, and diabetic complications were performed to assess the relationship between education and quality of care. RESULTS: Of 11 quality-of-care indicators, three were significantly associated with education: funduscopy (patients with tertiary versus primary education were more likely to get the exam: odds ratio, 1.8; 95% confidence interval [CI], 1.004-3.3) and two indicators of health-related quality of life (patients with tertiary versus primary education reported better health-related quality of life: Audit of Diabetes-Dependent Quality of Life: β=0.6 [95% CI, 0.2-0.97]; SF-12 mean physical component summary score: β=3.6 [95% CI, 0.9-6.4]). CONCLUSION: Our results suggest the presence of educational inequalities in quality of diabetes care. These findings may help health professionals focus on individuals with increased needs to decrease health inequalities

Ceftriaxone acts synergistically with levofloxacin in experimental meningitis and reduces levofloxacin-induced resistance in penicillin-resistant pneumococci

Ceftriaxone acted synergistically with levofloxacin in time-killing assays in vitro over 8 h against two penicillin-resistant pneumococcal strains (WB4 and KR4; MIC of penicillin: 4 mg/L). Synergy was confirmed with the chequerboard method, showing FIC indices of 0.25. In the experimental rabbit meningitis model, ceftriaxone (1× 125 mg/kg) was slightly less bactericidal (-0.30 Δlog10 cfu/mL.h) compared with levofloxacin (-0.45 Δlog10 cfu/mL.h) against the penicillin-resistant strain WB4. The combination therapy (levofloxacin and ceftriaxone) was significantly superior (-0.64 Δlog10 cfu/mL.h) to either monotherapy. In cycling experiments in vitro, the addition of ceftriaxone at a sub-MIC concentration (1/16 MIC) reduced levofloxacin-induced resistance in the two strains KR4 and WB4. After 12 cycles with levofloxacin monotherapy, the MIC increased 64-fold in both strains versus a 16-fold increase with the combination (levofloxacin + ceftriaxone 1/16 MIC). In both strains, levofloxacin-induced resistance was confirmed by mutations detected in the genes parC and gyrA, encoding for subunits of topoisomerase IV and gyrase, respectively. The addition of ceftriaxone suppressed mutations in parC but led to a new mutation in parE in both strain

Meropenem Prevents Levofloxacin-Induced Resistance in Penicillin-Resistant Pneumococci and Acts Synergistically with Levofloxacin in Experimental Meningitis

The aim of the present study was to investigate the potential synergy between meropenem and levofloxacin in vitro and in experimental meningitis and to determine the effect of meropenem on levofloxacin-induced resistance in vitro. Meropenem increased the efficacy of levofloxacin against the penicillin-resistant pneumococcal strain KR4 in time-killing assays in vitro and acted synergistically against a second penicillin-resistant strain WB4. In the checkerboard, only an additive effect (FIC indices: 1.0) was observed for both strains. In cycling experiments in vitro, levofloxacin alone led to a 64-fold increase in the MIC for both strains after 12 cycles. Addition of meropenem in sub-MIC concentrations (0.25×MIC) completely inhibited the selection of levofloxacin-resistant mutants in WB4 after 12 cycles. In KR4, the addition of meropenem led to just a twofold increase in the MIC for levofloxacin after 12 cycles. Mutations detected in the genes encoding for topoisomerase IV (parC) and gyrase (gyrA) confirmed the levofloxacin-induced resistance in both strains. Addition of meropenem was able to completely suppress levofloxacin-induced mutations in WB4 and led to only one mutation in parE in KR4. In experimental meningitis, meropenem, given in two doses (2×125mg/kg), produced a good bactericidal activity (−0.45 Δlog10 cfu/ml·h) comparable to one dose (1×10mg/kg) of levofloxacin (−0.44 Δlog10 cfu/ml·h) against the penicillin-resistant strain WB4. Meropenem combined with levofloxacin acted synergistically (−0.93 Δlog10 cfu/ml·h), sterilizing the CSF of all rabbit

Protective Efficacy of Individual CD8+ T Cell Specificities in Chronic Viral Infection.

Specific CD8(+) T cells (CTLs) play an important role in resolving protracted infection with hepatitis B and C virus in humans and lymphocytic choriomeningitis virus (LCMV) in mice. The contribution of individual CTL specificities to chronic virus control, as well as epitope-specific patterns in timing and persistence of antiviral selection pressure, remain, however, incompletely defined. To monitor and characterize the antiviral efficacy of individual CTL specificities throughout the course of chronic infection, we coinoculated mice with a mixture of wild-type LCMV and genetically engineered CTL epitope-deficient mutant virus. A quantitative longitudinal assessment of viral competition revealed that mice continuously exerted CTL selection pressure on the persisting virus population. The timing of selection pressure characterized individual epitope specificities, and its magnitude varied considerably between individual mice. This longitudinal assessment of "antiviral efficacy" provides a novel parameter to characterize CTL responses in chronic viral infection. It demonstrates remarkable perseverance of all antiviral CTL specificities studied, thus raising hope for therapeutic vaccination in the treatment of persistent viral diseases