Messverfahren zur Bestimmung der EMV-relevanten Störanteile in Hochvolt-Bordnetzen von Kraftfahrzeugen

In Hybrid- oder Elektrokraftfahrzeugen stellt der Aspekt der elektromagnetischen Verträglichkeit (EMV) des Hochvolt-(HV)-Netzwerks eine besondere Herausforderung dar [Hohloch, J. ; Köhler, W. ; Tenbohlen, S. ; Aidam, M. ; Krauß, T.: Charakterisierung und Vergleich leitungsgebundener Störungen an KFZ-Hochvoltbordnetzen. In: EMV 2012, Internationale Fachmesse und Kongress für Elektromagnetische Verträglichkeit. Düsseldorf, 2012]. Hohe übertragene Leistungen und steile Taktflanken lassen die HV-Leitungen zu Quellen hochfrequenter Störemission werden. Um diese Effekte besser erschließen zu können, ist es notwendig, die Vorgänge im Inneren des geschirmten HV-Systems zu erfassen. Dies kann durch eine breitbandige Messung der zeitaufgelösten Ströme und Spannungen direkt auf den HV-Leitungen erreicht werden. Die derzeitigen Lösungen für diese Messungen (Spannungsteiler, Rogowskispule, Stromzange, Shunt-Widerstand und Hallsensor) haben jedoch den Nachteil, dass dadurch insbesondere die EMV-relevanten hochfrequenten Störanteile der zu vermessenden Systemkomponenten nicht erfasst oder zumindest deutlich beeinflusst werden. Daher stellt dieser Beitrag ein neu entwickeltes Messverfahren vor, das diese Nachteile nicht aufweist. In Kapitel 2 werden Kalibrierung und Messung im Detail vorgestellt und verifiziert. In Kapitel 3 wird der Messaufbau zum Einsatz in Elektrofahrzeugen dargestellt. Weiterhin wird die Bedeutung der Rückwirkungsfreiheit des entwickelten Verfahrens hervorgehoben, bevor erste Messungen an einem Fahrzeug durchgeführt werden

Acute mountain sickness.

Acute mountain sickness (AMS) is a clinical syndrome occurring in otherwise healthy normal individuals who ascend rapidly to high altitude. Symptoms develop over a period ofa few hours or days. The usual symptoms include headache, anorexia, nausea, vomiting, lethargy, unsteadiness of gait, undue dyspnoea on moderate exertion and interrupted sleep. AMS is unrelated to physical fitness, sex or age except that young children over two years of age are unduly susceptible. One of the striking features ofAMS is the wide variation in individual susceptibility which is to some extent consistent. Some subjects never experience symptoms at any altitude while others have repeated attacks on ascending to quite modest altitudes. Rapid ascent to altitudes of 2500 to 3000m will produce symptoms in some subjects while after ascent over 23 days to 5000m most subjects will be affected, some to a marked degree. In general, the more rapid the ascent, the higher the altitude reached and the greater the physical exertion involved, the more severe AMS will be. Ifthe subjects stay at the altitude reached there is a tendency for acclimatization to occur and symptoms to remit over 1-7 days

Impact of Cerebral Microbleeds in Stroke Patients with Atrial Fibrillation

OBJECTIVES: Cerebral microbleeds are associated with the risks of ischemic stroke and intracranial hemorrhage, causing clinical dilemmas for antithrombotic treatment decisions. We aimed to evaluate the risks of intracranial hemorrhage and ischemic stroke associated with microbleeds in patients with atrial fibrillation treated with Vitamin K antagonists, direct oral anticoagulants, antiplatelets, and combination therapy (i.e. concurrent oral anticoagulant and antiplatelet) METHODS: We included patients with documented atrial fibrillation from the pooled individual patient data analysis by the Microbleeds International Collaborative Network. Risks of subsequent intracranial hemorrhage and ischemic stroke were compared between patients with and without microbleeds, stratified by antithrombotic use. RESULTS: A total of 7,839 patients were included. The presence of microbleeds was associated with an increased relative risk of intracranial hemorrhage (aHR 2.74, 95% confidence interval 1.76 - 4.26) and ischemic stroke (aHR 1.29, 95% confidence interval 1.04 - 1.59). For the entire cohort, the absolute incidence of ischemic stroke was higher than intracranial hemorrhage regardless of microbleeds burden. However, for the subgroup of patients taking combination of anticoagulant and antiplatelet therapy, the absolute risk of intracranial hemorrhage exceeded that of ischemic stroke in those with 2-4 microbleeds (25 vs 12 per 1,000 patient-years) and ≥11 microbleeds (94 vs 48 per 1,000 patient-years). INTERPRETATION: Patients with atrial fibrillation and high burden of microbleeds receiving combination therapy have a tendency of higher rate of intracranial hemorrhage than ischemic stroke, with potential for net harm. Further studies are needed to help optimize stroke preventive strategies in this high-risk group. This article is protected by copyright. All rights reserved

The Turmoil and the Torment

Abstract not availabl

Copper Phenanthroline as a Fast and High-Performance Redox Mediator for Dye-Sensitized Solar Cells

The most commonly used redox mediators in dye-sensitized solar cells (DSCs), iodide/triiodide and cobalt trisbipyridine ([Co(bpy)(3)](2+/3+)), were successfully replaced by bis (2,9-dimethy1-1,10-phenanthroline) copp er (I/H) ([Cu(dmp)(2)](1+/2+)). The use of the copper complex based electrolyte led to an exceptionally high photovoltaic performance of 8.3% for LEG4-sensitized TiO2 solar cells, with a remarkably high open-circuit potential of above 1.0 V at 1000 W m(-2) under AM1.5G conditions. The copper complex based redox electrolyte has higher diffusion coefficients and is considerably faster in dye regeneration than comparable cobalt trisbipyridine based electrolytes. A driving force for dye regeneration of only 0.2 eV is sufficient to obtain unit yield, pointing to new possibilities for improvement in DSC efficiencies. The interaction of the excited dye with components of the electrolyte was monitored using steady-state emission measurements and time-correlated single-photon counting (TC-SPC). Our results indicate bimolecular reductive quenching of the excited LEG4 dye by the [Cu(dmp)(2)](2+) complex through a dynamic mechanism. Excited-state dye molecules can readily undergo bimolecular electron transfer with a suitable donor molecule. In DSCs this process can occur when the excited dye is unable to inject electrons into the TiO2. With a high electrolyte concentration the excited dye can be intercepted with an electron from the electrolyte resulting in the reduced state of the dye. Quenching of the reduced dye by the electrolyte competes with electron injection and results in a lower photocurrent. Quenching of excited LEG4 by complexes of [Cu(dmp)(2)](+), [Co(bpy)(3)](2+), and [Co(bpy)(3)](3+) followed a static mechanism, due ground-state dye-quencher binding. Inhibition of unwanted quenching processes by structural modifications may open ways to further increase the overall efficiency

Ultrafast Interligand Electron Transfer in cis-[Ru(4,4’-dicarboxylate-2,2’-bipyridine)2(NCS)2]4- and Implications for Electron Injection Limitations in Dye Sensitized Solar Cells

Interligand electron transfer (ILET) of the lowest metal-to-ligand charge transfer (MLCT) state of N712 (cis-[Ru(dcb)2(NCS)2]4−, where dcb = 4,4′-dicarboxylate-2,2′-bipyridine) in a deuterated acetonitrile solution has been studied by means of femtosecond transient absorption anisotropy in the mid-IR. Time-independent B3LYP density functional calculations were performed to assign vibrational bands and determine their respective transition dipole moments. The transient absorption spectral band at 1327 cm−1, assigned to a symmetric carboxylate stretch, showed significant anisotropy. A rapid anisotropy increase (τ1 ≈ 2 ps) was tentatively assigned to vibrational and solvent relaxation, considering the excess energy available after the excited singlet–triplet conversion. Thereafter, the anisotropy decayed to zero with a time constant τ2 ≈ 240 ps, which was assigned to the rotational correlation time of the complex in deuterated acetonitrile. No other distinctive changes to the anisotropy were observed and the amplitude of the slow component at time zero agrees well with that predicted for a random mixture of MLCT localization on either of the two dcb ligands. The results therefore suggest that MLCT randomization over the two dcb ligands occurs on the sub-ps time scale. This is much faster than proposed by previous reports on the related N3 complex [Benkö et al., J. Phys. Chem. B, 2004, 108, 2862, and Waterland et al., J. Phys. Chem. A, 2001, 105, 4019], but in agreement with that found by Wallin and co-workers [J. Phys. Chem. A, 2005, 109, 4697] for the [Ru(bpy)3]2+ (bpy = 2,2′-bipyridine) complex. This suggests that electron injection from the excited dye into TiO2 in dye-sensitized solar cells is not limited by ILET. <img src="https://pubs.rsc.org/en/Image/Get?imageInfo.ImageType=GA&amp;imageInfo.ImageIdentifier.ManuscriptID=C8SC00274F" /

A Cell-Adhesive Plasma Polymerized Allylamine Coating Reduces the In Vivo Inflammatory Response Induced by Ti6Al4V Modified with Plasma Immersion Ion Implantation of Copper

Copper (Cu) could be suitable to create anti-infective implants based on Titanium (Ti), for example by incorporating Cu into the implant surface using plasma immersion ion implantation (Cu-PIII). The cytotoxicity of Cu might be circumvented by an additional cell-adhesive plasma polymerized allylamine film (PPAAm). Thus, this study aimed to examine in vivo local inflammatory reactions for Ti6Al4V implants treated with Cu-PIII (Ti-Cu), alone or with an additional PPAAm film (Ti-Cu-PPAAm), compared to untreated implants (Ti). Successful Cu-PIII and PPAAm treatment was confirmed with X-ray Photoelectron Spectroscopy. Storage of Ti-Cu and Ti-Cu-PPAAm samples in double-distilled water for five days revealed a reduction of Cu release by PPAAm. Subsequently, Ti, Ti-Cu and Ti-Cu-PPAAm samples were simultaneously implanted into the neck musculature of 24 rats. After 7, 14 and 56 days, peri-implant tissue was retrieved from 8 rats/day for morphometric immunohistochemistry of different inflammatory cells. On day 56, Ti-Cu induced significantly stronger reactions compared to Ti (tissue macrophages, antigen-presenting cells, T lymphocytes) and to Ti-Cu-PPAAm (tissue macrophages, T lymphocytes, mast cells). The response for Ti-Cu-PPAAm was comparable with Ti. In conclusion, PPAAm reduced the inflammatory reactions caused by Cu-PIII. Combining both plasma processes could be useful to create antibacterial and tissue compatible Ti-based implants