125 research outputs found

    Using Corticomuscular and Intermuscular Coherence to Assess Cortical Contribution to Ankle Plantar Flexor Activity During Gait

    Get PDF
    The present study used coherence and directionality analyses to explore whether the motor cortex contributes to plantar flexor muscle activity during the stance phase and push-off phase during gait. Subjects walked on a treadmill, while EEG over the leg motorcortex area and EMG from the medial gastrocnemius and soleus muscles was recorded. Corticomuscular and intermuscular coherence were calculated from pair-wise recordings. Significant EEG-EMG and EMG-EMG coherence in the beta and gamma frequency bands was found throughout the stance phase with the largest coherence towards push-off. Analysis of directionality revealed that EEG activity preceded EMG activity throughout the stance phase until the time of push-off. These findings suggest that the motor cortex contributes to ankle plantar flexor muscle activity and forward propulsion during gait

    Review of biorthogonal coupled cluster representations for electronic excitation

    Full text link
    Single reference coupled-cluster (CC) methods for electronic excitation are based on a biorthogonal representation (bCC) of the (shifted) Hamiltonian in terms of excited CC states, also referred to as correlated excited (CE) states, and an associated set of states biorthogonal to the CE states, the latter being essentially configuration interaction (CI) configurations. The bCC representation generates a non-hermitian secular matrix, the eigenvalues representing excitation energies, while the corresponding spectral intensities are to be derived from both the left and right eigenvectors. Using the perspective of the bCC representation, a systematic and comprehensive analysis of the excited-state CC methods is given, extending and generalizing previous such studies. Here, the essential topics are the truncation error characteristics and the separability properties, the latter being crucial for designing size-consistent approximation schemes. Based on the general order relations for the bCC secular matrix and the (left and right) eigenvector matrices, formulas for the perturbation-theoretical (PT) order of the truncation errors (TEO) are derived for energies, transition moments, and property matrix elements of arbitrary excitation classes and truncation levels. In the analysis of the separability properties of the transition moments, the decisive role of the so-called dual ground state is revealed. Due to the use of CE states the bCC approach can be compared to so-called intermediate state representation (ISR) methods based exclusively on suitably orthonormalized CE states. As the present analysis shows, the bCC approach has decisive advantages over the conventional CI treatment, but also distinctly weaker TEO and separability properties in comparison with a full (and hermitian) ISR method

    In vitro activity of isavuconazole against 208 Aspergillus flavus isolates in comparison with 7 other antifungal agents: assessment according to the methodology of the European Committee on Antimicrobial Susceptibility Testing

    No full text
    Item does not contain fulltextAspergillus flavus is the second most common species causing invasive aspergillosis after A. fumigatus. In certain countries like India, Sudan, and Saudi Arabia, A. flavus is most frequently isolated from patients with fungal rhinosinusitis and endophthalmitis. A. flavus exhibit an increased resistance to antifungal agents compared to A. fumigatus. We determined the in vitro activity of isavuconazole, voriconazole, posaconazole, itraconazole, amphotericin B, caspofungin, micafungin, and anidulafungin against 208 isolates of A. flavus by the EUCAST method and compared with the results obtained by the CLSI method. Isavuconazole and voriconazole MICs were /=2 mug/mL in 91%; 36% of them exhibited MICs of >/=8 mug/mL. All echinocandins demonstrated good anti-A. flavus activity. The essential agreement of the MIC/MEC results by EUCAST with CLSI broth dilution method assessed at +/-2 dilutions was good for itraconazole (97.8%), voriconazole (100%), posaconazole (98.3%), isavuconazole (98.9%), caspofungin (99.4%), and anidulafungin (100%), but poor for amphotericin B (53.5%) and micafungin (79.1%)

    In vitro susceptibility of 188 clinical and environmental isolates of Aspergillus flavus for the new triazole isavuconazole and seven other antifungal drugs

    No full text
    Item does not contain fulltextRecently isavuconazole, an experimental triazole agent, was found to be active against Aspergillus species. As Aspergillus flavus is the second-most common Aspergillus species isolated from human infection and the fungus has not been widely tested against the drug, we studied a large collection of clinical (n = 178) and environmental (n = 10) strains of A. flavus against isavuconazole and compared the results with seven other Aspergillus-active antifungal agents (some of them triazoles, others echinocandins or polyene antifungals: voriconazole, posaconazole, itraconazole, caspofungin, anidulafungin, micafungin and amphotericin B) using Clinical and Laboratory Standards Institute methods. Strains with high minimal inhibitory concentrations (MICs) were tested by E-test as well. The strains were collected from two different geographical locations (India and the Netherlands). Three isolates (1.6%) had high MIC (2 mg l(-1) by microbroth dilution and 8 mg l(-1) by E-test) for amphotericin B. Isavuconazole showed good activity against A. flavus strains with MIC(50) and MIC(90) values of 1 mg l(-1). As compared with voriconazole (the drug recommended for primary therapy of aspergillosis), isavuconazole had better activity (99.5% of strains had MIC of </= 1 mg l(-1) for isavuconazole, compared to 74% of strains with same MIC for voriconazole). All strains were, following recently proposed clinical breakpoints, susceptible for the triazoles tested except three strains, which had MICs of 4 mg l(-1) for voriconazole. Testing these strains with high MIC by E-test, gave results of 0.5-2 mg l(-1). Posaconazole had the lowest MIC(50) and MIC(90) of 0.125 mg l(-1) and 0.25 mg l(-1), respectively. Among echinocandins, 97% of strains had a minimum effective concentration (MEC) of </= 0.5 mg l(-1) for caspofungin, and all strains had a MEC of </= 0.016 mg l(-1) and </= 0.125 mg l(-1) for anidulafungin and micafungin, respectively

    Intra- and interlaboratory agreement in assessing the in vitro activity of micafungin against common and rare Candida species with the EUCAST, CLSI, and Etest methods

    No full text
    The emergence of resistant strains among common and rare Candida species necessitates continuous monitoring of the in vitro susceptibilities of those isolates. We therefore assessed the in vitro activities of micafungin against 1,099 molecularly identified isolates belonging to 5 common and 20 rare Candida species by the EUCAST, CLSI, and Etest methods, assessing both the intralaboratory agreement and the interlaboratory agreement for two centers. The median micafungin EUCAST MICs were as follows, from the lowest to the highest: for Candida albicans, 0.004 mg/liter; for C. glabrata, 0.016 mg/liter; for C. tropicalis, 0.031 mg/liter; for C. krusei, 0.125 mg/liter; for C. parapsilosis, 2 mg/liter. Among rare Candida species, high MICs were found for C. guilliermondii, C. lipolytica, C. orthopsilosis, C. metapsilosis, and C. fermentati. No resistant isolates were found by the CLSI method, whereas resistance rates of 1 to 2% were found by the EUCAST method. Overall, the EUCAST method resulted in MICs 1 to 2 dilutions higher than those found by the CLSI and Etest methods. The intra- and interlaboratory agreement between methods was &gt;92%, except for the interlaboratory agreement between the EUCAST and CLSI methods (81%), where 17 to 31% of the differences were &gt;2 2-fold dilutions for C. albicans, C. glabrata, C. tropicalis, and other rare Candida species and &lt;6% for C. parapsilosis and C. krusei. For the other interlaboratory comparisons, the EUCAST method resulted in higher MICs than the Etest method for all species, but &lt;7% of these differences were &gt;2 2-fold dilutions. Overall, the CLSI method resulted inlower MICs than the Etest method, with 11% of all isolates demonstrating &gt;2 2-fold-dilution differences (6 to 20% for C. albicans, C. tropicalis, and rare Candida species; &lt;5% for C. glabrata, C. krusei, and C. parapsilosis) and smaller differences found after 24 h. Despite these differences, categorical agreement was excellent (&gt;97%), with only 1 to 2% very major errors between the EUCAST method and the other two methods. Copyright © 2016, American Society for Microbiology. All Rights Reserved
    corecore