419 research outputs found

    High-order nonlinear phase shift caused by cascaded third-order processes

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    We show, for the first time to our knowledge, that the fundamental beam that participates in the process of third-harmonic generation experiences an additional high-order nonlinear phase shift. The magnitude of the shift is proportional to the square of the pump intensity and the length of the sample and depends on the deviation from the exact phase-matched condition. This phase shift arises from cascaded thirdorder processes. Its value can exceed the value of the phase shift that originates from inherent fifth-order susceptibility of the nonlinear medium. Its sign is controllable by the sign of the phase mismatch of the third-harmonic generation process

    Levodopa‐induced dyskinesia are mediated by cortical gamma oscillations in experimental Parkinsonism

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    Background Levodopa is the most efficacious drug in the symptomatic therapy of motor symptoms in Parkinson's disease (PD); however, long‐term treatment is often complicated by troublesome levodopa‐induced dyskinesia (LID). Recent evidence suggests that LID might be related to increased cortical gamma oscillations. Objective The objective of this study was to test the hypothesis that cortical high‐gamma network activity relates to LID in the 6‐hydroxydopamine model and to identify new biomarkers for adaptive deep brain stimulation (DBS) therapy in PD. Methods We recorded and analyzed primary motor cortex (M1) electrocorticogram data and motor behavior in freely moving 6‐OHDA lesioned rats before and during a daily treatment with levodopa for 3 weeks. The results were correlated with the abnormal involuntary movement score (AIMS) and used for generalized linear modeling (GLM). Results Levodopa reverted motor impairment, suppressed beta activity, and, with repeated administration, led to a progressive enhancement of LID. Concurrently, we observed a highly significant stepwise amplitude increase in finely tuned gamma (FTG) activity and gamma centroid frequency. Whereas AIMS and FTG reached their maximum after the 4th injection and remained on a stable plateau thereafter, the centroid frequency of the FTG power continued to increase thereafter. Among the analyzed gamma activity parameters, the fraction of longest gamma bursts showed the strongest correlation with AIMS. Using a GLM, it was possible to accurately predict AIMS from cortical recordings. Conclusions FTG activity is tightly linked to LID and should be studied as a biomarker for adaptive DBS

    Pressure-volume loop validation of TAPSE/PASP for right ventricular arterial coupling in heart failure with pulmonary hypertension

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    Aims The aim of this study was to validate the tricuspid annular plane systolic excursion/systolic pulmonary artery (PA) pressure (TAPSE/PASP) ratio with the invasive pressure-volume (PV) loop-derived end-systolic right ventricular (RV) elastance/PA elastance (Ees/Ea) ratio in patients with heart failure with reduced ejection fraction (HFREF) and secondary pulmonary hypertension (PH).Methods and results The relationship of TAPSE and TAPSE/PASP with RV-PV loop (single-beat)-derived contractility Ees, afterload Ea, and Ees/Ea was assessed in 110 patients with HFREF with and without secondary PH. The results were compared with other surrogate parameters such as the fractional area change/PASP ratio. The association of the surrogates with all-cause mortality was evaluated. In patients with PH (n=74, 67%), TAPSE significantly correlated with Ees (r = 0.356), inverse with Ea (r = -0.514) but was most closely associated with Ees/Ea (r = 0.77). Placing TAPSE in a ratio with PASP slightly reduced the relationship to Ees/Ea (r = 0.71) but was more closely related to the parameters of PA vascular Load, diastolic RV function, and RV energetics. The area under the curve of TAPSE/PASP and TAPSE for discriminating overall survival in receiver operating characteristic analysis was not different (P = 0.78. Prognostic relevant cut-offs were 17mm for TAPSE and 0.38 mmimmHg for TAPSE/PASP. Both parameters in multivariate cox regression remained independently prognostically relevant.Conclusion TAPSE is an easily and reliably obtainable and valid surrogate parameter for RV-PA coupling in PH due to HFREF. Putting TAPSE into a ratio with PASP did not further improve the coupling information or prognostic assessment.Cardiolog

    Predictors and prognosis of right ventricular function in pulmonary hypertension due to heart failure with reduced ejection fraction

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    Aims Failure of right ventricular (RV) function worsens outcome in pulmonary hypertension (PH). The adaptation of RV contractility to afterload, the RV-pulmonary artery (PA) coupling, is defined by the ratio of RV end-systolic to PA elastances (Ees/Ea). Using pressure-volume loop (PV-L) technique we aimed to identify an Ees/Ea cut-off predictive for overall survival and to assess hemodynamic and morphologic conditions for adapted RV function in secondary PH due to heart failure with reduced ejection fraction (HFREF).Methods and results This post hoc analysis is based on 112 patients of the prospective Magdeburger Resynchronization Responder Trial. All patients underwent right and left heart echocardiography and a baseline PV-L and RV catheter measurement. A subgroup of patients (n = 50) without a pre-implanted cardiac device underwent magnetic resonance imaging at baseline. The analysis revealed that 0.68 is an optimal Ees/Ea cut-off (area under the curve: 0.697, P = 0.68 vs. = 0.68 showed comparable RV-Ees/Ea ratios (0.88 vs. 0.9, P = 0.39), RV size/function, and survival. In contrast, secondary PH with RV-PA coupling ratio Ees/Ea 160 mL, RV-mass/volume-ratio 171 mL, odds ratio (OR) 0.96, P = 0.021], high pulsatile load (PA compliance = 0.68) in PH was associated with preserved RV size/function and mid-term survival, comparable with HFREF without PH.Cardiolog

    Fabrication of Nickel Nanostructure Arrays Via a Modified Nanosphere Lithography

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    In this paper, we present a modified nanosphere lithographic scheme that is based on the self-assembly and electroforming techniques. The scheme was demonstrated to fabricate a nickel template of ordered nanobowl arrays together with a nickel nanostructure array-patterned glass substrate. The hemispherical nanobowls exhibit uniform sizes and smooth interior surfaces, and the shallow nanobowls with a flat bottom on the glass substrate are interconnected as a net structure with uniform thickness. A multiphysics model based on the level set method (LSM) was built up to understand this fabricating process by tracking the interface between the growing nickel and the electrolyte. The fabricated nickel nanobowl template can be used as a mold of long lifetime in soft lithography due to the high strength of nickel. The nanostructure–patterned glass substrate can be used in optical and magnetic devices due to their shape effects. This fabrication scheme can also be extended to a wide range of metals and alloys

    Paper-based sensors for rapid detection of virulence factor produced by Pseudomonas aeruginosa

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    Pyocyanin is a toxin produced by Pseudomonas aeruginosa. Here we describe a novel paper-based electrochemical sensor for pyocyanin detection, manufactured with a simple and inexpensive approach based on electrode printing on paper. The resulting sensors constitute an effective electrochemical method to quantify pyocyanin in bacterial cultures without the conventional time consuming pretreatment of the samples. The electrochemical properties of the paper-based sensors were evaluated by ferri/ferrocyanide as a redox mediator, and showed reliable sensing performance. The paper-based sensors readily allow for the determination of pyocyanin in bacterial cultures with high reproducibility, achieving a limit of detection of 95 nM and a sensitivity of 4.30 ÎŒA/ÎŒM in standard culture media. Compared to the similar commercial ceramic based sensors, it is a 2.3-fold enhanced performance. The simple in-house fabrication of sensors for pyocyanin quantification allows researchers to understand in vitro adaptation of P. aeruginosa infections via rapid screenings of bacterial cultures that otherwise are expensive and time-consuming

    Using fahp-vikor for operation selection in the flexible job-shop scheduling problem: A case study in textile industry

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    Scheduling of Flexible Job Shop Systems is a combinatorial problem which has been addressed by several heuristics and meta-heuristics. Nevertheless, the operation selection rules of both methods are limited to an ordered variant wherein priority-dispatching rules are not simultaneously deemed in the reported literature. Therefore, this paper presents the application of dispatching algorithm with operation selection based on Fuzzy Analytic Hierarchy Process (FAHP) and VIKOR methods while considering setup times and transfer batches. Dispatching, FAHP, and VIKOR algorithms are first defined. Second, a multi-criteria decision-making model is designed for operation prioritization. Then, FAHP is applied to calculate the criteria weights and overcome the uncertainty of human judgments. Afterwards, VIKOR is used to select the operation with the highest priority. A case study in the textile industry is shown to validate this approach. The results evidenced, compared to the company solution, a reduction of 61.05% in average delay

    Diversidade e estrutura genética em populaçÔes naturais de Hancornia speciosa var. speciosa Gomes no nordeste do Brasil

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    Hancornia speciosa Gomes is a fruit tree native from Brazil that belongs to Apocinaceae family, and is popularly known as Mangabeira. Its fruits are widely consumed raw or processed as fruit jam, juices and ice creams, which have made it a target of intense exploitation. The extractive activities and intense human activity on the environment of natural occurrence of H. speciosa has caused genetic erosion in the species and little is known about the ecology or genetic structure of natural populations. The objective of this research was the evaluation of the genetic diversity and genetic structure of H. speciosa var. speciosa. The genetic variability was assessed using 11 allozyme loci with a sample of 164 individuals distributed in six natural populations located in the States of Pernambuco and Alagoas, Northeastern Brazil. The results showed a high level of genetic diversity within the species (<img border=0 id="_x0000_i1026" src="/img/revistas/rbf/v34n4/a23img01.jpg" align=absmiddle>e= 0.36) seeing that the most of the genetic variability of H. speciosa var. speciosa is within its natural populations with low difference among populations ( <img border=0 id="_x0000_i1027" src="/img/revistas/rbf/v34n4/a23img02.jpg" align=absmiddle > or = 0.081). The inbreeding values within (<img border=0 id="_x0000_i1028" src="/img/revistas/rbf/v34n4/a23img03.jpg" align=absmiddle> = -0.555) and among populations (<img border=0 id="_x0000_i1029" src="/img/revistas/rbf/v34n4/a23img04.jpg" align=absmiddle> =-0.428) were low showing lacking of endogamy and a surplus of heterozygotes. The estimated gene flow ( <img border=0 id="_x0000_i1030" src="/img/revistas/rbf/v34n4/a23img05.jpg" align=absmiddle>m ) was high, ranging from 2.20 to 13.18, indicating to be enough to prevent the effects of genetic drift and genetic differentiation among populations. The multivariate analyses indicated that there is a relationship between genetic and geographical distances, which was confirmed by a spatial pattern analysis using Mantel test (r = 0.3598; p = 0.0920) with 1000 random permutations. The high genetic diversity index in these populations indicates potential for in situ genetic conservation

    Sequential targeted exome sequencing of 1001 patients affected by unexplained limb-girdle weakness

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    Several hundred genetic muscle diseases have been described, all of which are rare. Their clinical and genetic heterogeneity means that a genetic diagnosis is challenging. We established an international consortium, MYO-SEQ, to aid the work-ups of muscle disease patients and to better understand disease etiology. Exome sequencing was applied to 1001 undiagnosed patients recruited from more than 40 neuromuscular disease referral centers; standardized phenotypic information was collected for each patient. Exomes were examined for variants in 429 genes associated with muscle conditions. We identified suspected pathogenic variants in 52% of patients across 87 genes. We detected 401 novel variants, 116 of which were recurrent. Variants in CAPN3, DYSF, ANO5, DMD, RYR1, TTN, COL6A2, and SGCA collectively accounted for over half of the solved cases; while variants in newer disease genes, such as BVES and POGLUT1, were also found. The remaining well-characterized unsolved patients (48%) need further investigation. Using our unique infrastructure, we developed a pathway to expedite muscle disease diagnoses. Our data suggest that exome sequencing should be used for pathogenic variant detection in patients with suspected genetic muscle diseases, focusing first on the most common disease genes described here, and subsequently in rarer and newly characterized disease genes
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