805 research outputs found
Neuromonitoring und Neuroprotektion in der Kardioanästhesie: Bundesweite Umfrage des Arbeitskreises Kardioanästhesie der Deutschen Gesellschaft für Anästhesiologie und Intensivmedizin e.V
Zusammenfassung: Fragestellung: Primäres Ziel dieser in deutschen kardioanästhesiologischen Abteilungen durchgeführten Umfrage war, die aktuelle Praxis von Neuromonitoring und Neuroprotektion zu erheben. Methodik: Zwischen Oktober 2007 und Januar 2008 wurden hierzu Daten mithilfe eines 26Punkte umfassenden, anonymisierten Fragebogens erhoben. Ermittelt wurden: präoperative Evaluation der hirnversorgenden Arterien, intraoperatives Neuromonitoring, zerebroprotektive Maßnahmen, Perfusionsmanagement während extrakorporaler Zirkulation, postoperative Erhebung des neurologischen Status und Aus-/Weiterbildung im zerebralen Monitoring. Ergebnisse: 55% der Fragebögen wurden mit folgenden Angaben beantwortet: präoperative Duplexsonographie der Hirngefäße in 90% der Kliniken; intraoperatives Neuromonitoring mithilfe der Elektroenzephalographie (EEG; 60%) bei Typ-A-Dissektionen (38,1%), bei elektiven Operationen an der thorakalen bzw. thorakoabdominellen Aorta (34,1% resp. 31,6%) und in der Karotischirurgie (43,2%), weiterhin Einsatz der Nahinfrarotspektroskopie (40%), Ableitung evozierter Potenziale (30%) und transkranielle Dopplersonographie (17,5%). Auch kombinierte Verfahren wurden angewandt. Während Bypass-, Klappen und minimal-invasiven Operationen erfolgt meistens kein Monitoring des Zentralnervensystems. Zur Zerebroprotektion werden die Kühlung des Patienten an Herz-Lungen-Maschine (HLM; 100%), externe Kühlung des Kopfes (65%), Gabe von Kortikosteroiden (58%), Barbituraten (50%) und Antiepileptika (10%) eingesetzt. Als neuroprotektive Anästhesieverfahren gelten Inhalationsanästhesie (32,5%; Favorit: Sevofluran 76,5%) und total intravenöse Anästhesie (20%; Favoriten: Propofol und Barbiturate mit je 46,2%). Standardmäßig kühlen 72,5% der Krankenhäuser die Patienten bei Operationen mit Herz-Kreislauf-Stillstand, 37,5% bei allen Operationen mit HLM. Unter normothermen Bedingungen entspricht in 84,6% der Kliniken der HLM-Fluss dem errechneten Herzzeitvolumen (HZV), der anzustrebende mittlere arterielle Druck (MAP) liegt bei 60-70mmHg (43,9%) bzw. 50-60mmHg (41,5%). Bei einer Körpertemperatur unter 18°C wird der HLM-Fluss unter das errechnete HZV gesenkt (70%), während in 27% der Kliniken normotherme Flussraten gefahren werden. Der bevorzugte MAP unter Hypothermie liegt zwischen 50 und 60mmHg (59%). Intraoperatives Neuromonitoring wird im Narkoseprotokoll (77%) dokumentiert. Postoperativ wird der neurologische Status in 42,5% der Kliniken durch individuelle Einschätzung des Anästhesisten (77,5%) erhoben. Fortbildungen zum Thema Neuromonitoring werden in 32,5% der Kliniken regelmäßig organisiert, in 37,5% dem Arzt selbst überlassen. Schlussfolgerung: Das kardioanästhesiologische Vorgehen in Deutschland ist im Bereich Neuromonitoring und neuroprotektive Therapie nicht standardisiert. Ein "multimodales Neuromonitoring" wäre wünschenswer
Efficient Algorithms for Optimal Control of Quantum Dynamics: The "Krotov'' Method unencumbered
Efficient algorithms for the discovery of optimal control designs for
coherent control of quantum processes are of fundamental importance. One
important class of algorithms are sequential update algorithms generally
attributed to Krotov. Although widely and often successfully used, the
associated theory is often involved and leaves many crucial questions
unanswered, from the monotonicity and convergence of the algorithm to
discretization effects, leading to the introduction of ad-hoc penalty terms and
suboptimal update schemes detrimental to the performance of the algorithm. We
present a general framework for sequential update algorithms including specific
prescriptions for efficient update rules with inexpensive dynamic search length
control, taking into account discretization effects and eliminating the need
for ad-hoc penalty terms. The latter, while necessary to regularize the problem
in the limit of infinite time resolution, i.e., the continuum limit, are shown
to be undesirable and unnecessary in the practically relevant case of finite
time resolution. Numerical examples show that the ideas underlying many of
these results extend even beyond what can be rigorously proved.Comment: 19 pages, many figure
Can Frequency Domain Heart Rate Measures Detect Impaired Driver Performance?
An overnight driving simulation scenario with partial sleep deprivation was utilized to induce driver performance impairment. Heart rate (HR) was recorded over the entire experiment; frequency domain HR measures were derived and correlated to variation of lane deviation (VLD), a driving performance measure, and to the driver\u27s state, which was estimated by the Karolinska Sleepiness Scale (KSS). The aim of this study is to evaluate whether frequency domain heart rate measures can be used to detect impaired driver performance as well as reduced driver state. We generalize the concept of the conventional frequency domain HR measures – namely the very-low frequency (VLF), low frequency (LF) band and high frequency (HF) band – into finer-grained frequency bands of 0.02 Hz width. These newly defined frequency bands show a more detailed correlation to driving performance and to driver sleepiness state, taking subjectspecific differences into account
The star formation rate history in the FORS Deep and GOODS South Fields
We measure the star formation rate (SFR) as a function of redshift z up to z
\~4.5, based on B, I and (I+B) selected galaxy catalogues from the FORS Deep
Field (FDF) and the K-selected catalogue from the GOODS-South field. Distances
are computed from spectroscopically calibrated photometric redshifts accurate
to (Delta_z / (z_spec+1)) ~0.03 for the FDF and ~0.056 for the GOODS-South
field. The SFRs are derived from the luminosities at 1500 Angstroem. We find
that the total SFR estimates derived from B, I and I+B catalogues agree very
well (\lsim 0.1 dex) while the SFR from the K catalogue is lower by ~0.2 dex.
We show that the latter is solely due to the lower star-forming activity of
K-selected intermediate and low luminosity (L<L_*) galaxies. The SFR of bright
(L>L_*) galaxies is independent of the selection band, i.e. the same for B, I,
(I+B), and K-selected galaxy samples. At all redshifts, luminous galaxies
(L>L_*) contribute only ~1/3 to the total SFR. There is no evidence for
significant cosmic variance between the SFRs in the FDF and GOODs-South field,
~0.1 dex, consistent with theoretical expectations. The SFRs derived here are
in excellent agreement with previous measurements provided we assume the same
faint-end slope of the luminosity function as previous works (alpha ~ -1.6).
However, our deep FDF data indicate a shallower slope of alpha=-1.07, implying
a SFR lower by ~0.3 dex. We find the SFR to be roughly constant up to z ~4 and
then to decline slowly beyond, if dust extinctions are assumed to be constant
with redshift.Comment: 6 pages, 2 figures, Accepted for publication in ApJ
Affective encoding in the speech signal and in event-related brain potentials
A number of perceptual features have been utilized for the characterization of the emotional state of a speaker. However, for automatic recognition suitable objective features are needed. We have examined several features of the speech signal in relation to accentuation and traces of event-related brain potentials (ERPs) during affective speech perception. Concerning the features of the speech signal we focus on measures related to breathiness and roughness. The objective measures used were an estimation of the harmonics-to-noise ratio, the glottal-to-noise excitation ratio, a measure for spectral flatness, as well as the maximum prediction gain for a speech production model computed by the mutual information function and the ERPs. Results indicate that in particular the maximum prediction gain shows a good differentiation between neutral and non-neutral emotional speaker state. This differentiation is partly comparable to the ERP results that show a differentiation of neutral, positive and negative affect. Other objective measures are more related to accentuation than to emotional state of the speaker
Progesterone and interleukin-8 during and after cardiopulmonary bypass in infants and children
Measuring impairments of functioning and health in patients with axial spondyloarthritis by using the ASAS Health Index and the Environmental Item Set : translation and cross-cultural adaptation into 15 languages
Introduction: The Assessments of SpondyloArthritis international society Health Index (ASAS HI) measures functioning and health in patients with spondyloarthritis (SpA) across 17 aspects of health and 9 environmental factors (EF). The objective was to translate and adapt the original English version of the ASAS HI, including the EF Item Set, cross-culturally into 15 languages.
Methods: Translation and cross-cultural adaptation has been carried out following the forward-backward procedure. In the cognitive debriefing, 10 patients/country across a broad spectrum of sociodemographic background, were included.
Results: The ASAS HI and the EF Item Set were translated into Arabic, Chinese, Croatian, Dutch, French, German, Greek, Hungarian, Italian, Korean, Portuguese, Russian, Spanish, Thai and Turkish. Some difficulties were experienced with translation of the contextual factors indicating that these concepts may be more culturally-dependent. A total of 215 patients with axial SpA across 23 countries (62.3% men, mean (SD) age 42.4 (13.9) years) participated in the field test. Cognitive debriefing showed that items of the ASAS HI and EF Item Set are clear, relevant and comprehensive. All versions were accepted with minor modifications with respect to item wording and response option. The wording of three items had to be adapted to improve clarity. As a result of cognitive debriefing, a new response option 'not applicable' was added to two items of the ASAS HI to improve appropriateness.
Discussion: This study showed that the items of the ASAS HI including the EFs were readily adaptable throughout all countries, indicating that the concepts covered were comprehensive, clear and meaningful in different cultures
Self-consistent Green's function approaches
We present the fundamental techniques and working equations of many-body
Green's function theory for calculating ground state properties and the
spectral strength. Green's function methods closely relate to other polynomial
scaling approaches discussed in chapters 8 and 10. However, here we aim
directly at a global view of the many-fermion structure. We derive the working
equations for calculating many-body propagators, using both the Algebraic
Diagrammatic Construction technique and the self-consistent formalism at finite
temperature. Their implementation is discussed, as well as the inclusion of
three-nucleon interactions. The self-consistency feature is essential to
guarantee thermodynamic consistency. The pairing and neutron matter models
introduced in previous chapters are solved and compared with the other methods
in this book.Comment: 58 pages, 14 figures, Submitted to Lect. Notes Phys., "An advanced
course in computational nuclear physics: Bridging the scales from quarks to
neutron stars", M. Hjorth-Jensen, M. P. Lombardo, U. van Kolck, Editor
Targeting the Divergent Roles of STK3 Inhibits Breast Cancer Cell Growth and Opposes Doxorubicin-Induced Cardiotoxicity In Vitro
Breast cancer (BCa) is the most prevalent type of cancer in women. Several therapies used in the treatment of breast cancer are associated with clinically important rates of cardiovascular toxicity during or after treatment exposure, including anthracyclines. There is a need for new BCa therapeutics and treatments that mitigate chemotherapy-induced cardiotoxicity in BCa. In this study, we examine the effects of Serine/Threonine Kinase 3 (STK3) inhibition in the context of BCa therapy and cardioprotection from doxorubicin. STK3 (also known as MST2) is a key member of the Hippo Tumor-Suppressor Pathway, which regulates cell growth and proliferation by inhibiting YAP/TAZ co-transcription factors. Canonically, STK3 should restrict BCa growth; however, we observed that STK3 is amplified in BCa and associated with worse patient outcomes, suggesting a noncanonical pro-tumorigenic role. We found BCa cell lines have varying dependence on STK3. SUM52PE cells had the highest expression and dependence on STK3 in genetic and pharmacological assays. MCF-7 and MDA-MB-231 were less sensitive to STK3 targeting in standard proliferation assays, but were STK3 dependent in colony formation and matrigel invasion assays. In contrast, STK3 inhibition mitigated the toxic effects of doxorubicin in H9C2 rat cardiomyocytes by increasing YAP expression. Importantly, STK3 inhibition in BCa cells did not interfere with the therapeutic effects of doxorubicin. Our studies highlight STK3 is a potential molecular target for BCa with dual therapeutic effects: suppression of BCa growth and progression, and chemoprotection in cardiomyocytes
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