537 research outputs found

    The Techniques for Overcoming Depression Questionnaire: Mokken Scale Analysis, Reliability, and Concurrent Validity in Depressed Cardiac Patients.

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    The Techniques for Overcoming Depression (TOD) questionnaire assesses the frequency with which patients being treated for depression use cognitive-behavioral techniques in daily life. This study examined its latent structure, reliability and concurrent validity in depressed cardiac patients. The TOD was administered at the initial and final treatment sessions in three trials of cognitive behavior therapy (CBT) (n = 260) for depression in cardiac patients. Mokken scaling was used to determine its dimensionality. The TOD is unidimensional in depressed cardiac patients, both at the initial evaluation (H = .46) and the end of treatment (H = .47). It is sensitive to change and the total score correlates with therapist ratings of the patient’s socialization to CBT (r = .40, p \u3c .05), homework adherence (r = .36, p \u3c .05), and use of cognitive-behavioral techniques (r = .51, p \u3c .01). TOD scores were associated with post-treatment depression scores in two of the trials (p \u3c .01 in both analyses). The TOD is a unidimensional, reliable, valid, and clinically informative measure of self-reported use of cognitive-behavioral techniques for overcoming depression in cardiac patients. Studies of the TOD in other depressed patient populations are needed

    Mechanism of thermally activated c-axis dissipation in layered High-Tc_c superconductors at high fields

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    We propose a simple model which explains experimental behavior of cc-axis resistivity in layered High-Tc_c superconductors at high fields in a limited temperature range. It is generally accepted that the in-plane dissipation at low temperatures is caused by small concentration of mobile pancake vortices whose diffusive motion is thermally activated. We demonstrate that in such situation a finite conductivity appears also in cc-direction due to the phase slips between the planes caused by the mobile pancakes. The model gives universal relation between the components of conductivity which is in good agreement with experimental data.Comment: RevTeX, 4 pages, 2 Postscript figure

    Web technologies and trends of SCADA-systems development in the field of APCS

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    This article discusses the use of Internet technologies for modern automated process control systems. As a result of the analysis, the author defines Scada systems and the Industrial Internet of Things. The main advantage of using Internet technologies in APCS is the ability to control and monitor from anywhere using a computer or mobile phone

    Temporal self-restoration of compressed optical filaments

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    We numerically investigate the propagation of a self-compressed optical filament through a gas-glass-gas interface. Few-cycle light pulses survive a sudden and short order-of-magnitude increase of nonlinearity and dispersion, even when all conservative estimates predict temporal spreading or spatial breakup. Spatio-temporal distortions are shown to self-heal upon further propagation when the pulse refocuses in the second gas. This self-healing mechanism has important implications for pulse compression techniques handled by filamentation and explains the robustness of such sources.Comment: 4 Pages, 4 figure

    Penetration of Josephson vortices and measurement of the c-axis penetration depth in Bi2Sr2CaCu2O8+δBi_{2}Sr_{2}CaCu_{2}O_{8+\delta}: Interplay of Josephson coupling, surface barrier and defects

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    The first penetration field H_{J}(T) of Josephson vortices is measured through the onset of microwave absorption in the locked state, in slightly overdoped Bi2Sr2CaCu2O8+δ\rm{Bi_{2}Sr_{2}CaCu_{2}O_{8+\delta}} single crystals (T_{c} ~ 84 K). The magnitude of H_{J}(T) is too large to be accounted for by the first thermodynamic critical field H_{c1}(T). We discuss the possibility of a Bean-Livingston barrier, also supported by irreversible behavior upon flux exit, and the role of defects, which relates H_{J}(T) to the c-axis penetration depth λc(T)\lambda_{c}(T). The temperature dependence of the latter, determined by a cavity perturbation technique and a theoretical estimate of the defect-limited penetration field are used to deduce from H_{J}(T) the absolute value of λc(0)=(35±15)μm\lambda_{c}(0)=(35 \pm 15) \mu m.Comment: 9 pages, 6 figure

    Increased Ventricular Premature Contraction Frequency During REM Sleep in Patients with Coronary Artery Disease and Obstructive Sleep Apnea

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    Background Patients with obstructive sleep apnea are reported to have a peak of sudden cardiac death at night, in contrast to patients without apnea whose peak is in the morning. We hypothesized that ventricular premature contraction (VPC) frequency would correlate with measures of apnea and sympathetic activity.Methods Electrocardiograms from a sleep study of 125 patients with coronary artery disease were evaluated. Patients were categorized by apnea-hypopnea index (AHI) into Moderate (AHI <15) or Severe (AHI>15) apnea groups. Sleep stages studied were Wake, S1, S2, S34, and rapid eye movement (REM). Parameters of a potent autonomically-based risk predictor for sudden cardiac death called heart rate turbulence were calculated.Results There were 74 Moderate and 51 Severe obstructive sleep apnea patients. VPC frequency was affected significantly by sleep stage (Wake, S2 and REM, F=5.8, p<.005) and by AHI (F=8.7, p<.005). In Severe apnea patients, VPC frequency was higher in REM than in Wake (p=.011). In contrast, patients with Moderate apnea had fewer VPCs and exhibited no sleep stage dependence (p=.19). Oxygen desaturation duration per apnea episode correlated positively with AHI (r2=.71, p<.0001), and was longer in REM than in non-REM (p<.0001). The heart rate turbulence parameter TS correlated negatively with oxygen desaturation duration in REM (r2=.06, p=.014).Conclusions Higher VPC frequency coupled with higher sympathetic activity caused by longer apnea episodes in REM sleep may be one reason for increased nocturnal death in apneic patients

    220 fs Er-Yb:glass laser mode-locked by a broadband low-loss Si/Ge saturable absorber

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    We demonstrate femtosecond performance of an ultra-broadband high-index-contrast saturable Bragg reflector consisting of a silicon/silicon-dioxide/germanium structure that is fully compatible with CMOS processing. This device offers a reflectivity bandwidth of over 700 nm and sub-picosecond recovery time of the saturable loss. It is used to achieve mode-locking of an Er-Yb:glass laser centered at 1540 nm, generating 220 fs pulses, with the broadest output spectrum to date

    First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

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    Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto- noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far

    Influence of extracellular rnas, released by rheumatoid arthritis synovial fibroblasts, on their adhesive and invasive properties

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    © 2016 by The American Association of Immunologists, Inc.Extracellular RNA (exRNA) has been characterized as a molecular alarm signal upon cellular stress or tissue injury and to exert biological functions as a proinflammatory, prothrombotic, and vessel permeability-regulating factor. In this study, we investigated the contribution of exRNA and its antagonist RNase1 in a chronic inflammatory joint disease, rheumatoid arthritis (RA). Upon immunohistochemical inspection of RA, osteoarthritis (OA), and psoriatic arthritis synovium, exRNA was detectable only in the RA synovial lining layer, whereas extracellular DNAwas detectable in various areas of synovial tissue. In vitro, exRNA (150-5000 nt) was released by RA synovial fibroblasts (RASF) under hypoxic conditions but not under normoxia or TNF-A treatment. RNase activity was increased in synovial fluid from RA and OA patients compared with psoriatic arthritis patients, whereas RNase activity of RASF and OASF cultures was not altered by hypoxia. Reduction of exRNA by RNase1 treatment decreased adhesion of RASF to cartilage, but it had no influence on their cell proliferation or adhesion to endothelial cells. In vivo, treatment with RNase1 reduced RASF invasion into coimplanted cartilage in the SCID mouse model of RA. We also analyzed the expression of neuropilins in synovial tissue and SF, as they may interact with vascular endothelial growth factor signaling and exRNA. The data support the concepts that the exRNA/RNase1 system participates in RA pathophysiology and that RASF are influenced by exRNA in a prodestructive manner. The Journal of Immunology, 2016, 197: 2589-2597
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