252 research outputs found

    On the impact of controlled wall roughness shape on the flow of a soft-material

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    We explore the impact of geometrical corrugations on the near-wall flow properties of a soft-material driven in a confined rough microchannel. By means of numerical simulations, we perform a quantitative analysis of the relation between the flow rate Φ\Phi and the wall stress σw\sigma_w for a number of setups, by changing both the roughness values as well as the roughness shape. Roughness suppresses the flow, with the existence of a characteristic value of σw\sigma_w at which flow sets in. Just above the onset of flow, we quantitatively analyze the relation between Φ\Phi and σw\sigma_w. While for smooth walls a linear dependency is observed, steeper behaviours are found to set in by increasing wall roughness. The variation of the steepness, in turn, depends on the shape of the wall roughness, wherein gentle steepness changes are promoted by a variable space localization of the roughness

    A sharp interface approach for wetting dynamics of coated droplets and soft particles

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    The wetting dynamics of liquid particles, from coated droplets to soft capsules, holds significant technological interest. Motivated by the need to simulate liquid metal droplets with an oxidized surface layer, in this work, we introduce a computational scheme that allows us to simulate droplet dynamics with general surface properties and model different levels of interface stiffness, also describing cases that are intermediate between pure droplets and capsules. Our approach is based on a combination of the immersed boundary and the lattice Boltzmann methods. Here, we validate our approach against the theoretical predictions in the context of shear flow and static wetting properties, and we show its effectiveness in accessing the wetting dynamics, exploring the ability of the scheme to address a broad phenomenology

    Time domain add-drop multiplexing scheme enhanced using a saw-tooth pulse shaper

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    We experimentally demonstrate the use of saw-tooth optical pulses, which are shaped using a fiber Bragg grating, to achieve robust and high performance time-domain add-drop multiplexing in a scheme based on cross-phase (XPM) modulation in an optical fiber, with subsequent offset filtering. As compared to the use of more conventional pulse shapes, such as Gaussian pulses of a similar pulse width, the purpose-shaped saw-tooth pulses allow higher extinction ratios for the add and drop windows and significant improvements in the receiver sensitivity for the dropped and added channels

    Immune-related adverse events in the treatment of non-Hodgkin lymphoma with immune checkpoint inhibitors

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    Immune checkpoint inhibitors (ICIs) show efficacy in the treatment of non-Hodgkin lymphomas (NHL). However, these agents are associated with a unique group of side effects called immune-related adverse events (irAEs). We conducted an observational retrospective/prospective study on patients with relapsed/refractory NHL treated with ICI to determine the incidence of irAEs assessing the type, severity, and timing of onset, outcome and relationship with study drugs of these events. Thirty-two patients underwent ICI as single agent (N = 20) or in combination (N = 12). Ten patients (31.3%) developed at least one irAE for a total of 17 irAEs. Median time to presentation of irAEs was 69 days (range 0–407) with a median resolution time of 16 days (range 0–98). Progression free survival at 24 months for patients who developed an irAE was 40% and 31.8% for who did not. Overall survival for the two groups did not differ (at 24 months 40.0% and 62.5% for patients without and with irAE, respectively), but the median for who developed an irAE was not reached. The incidence of irAEs was associated with better long-term survival in NHL treated with ICIs but patients’ disease conditions need to be carefully evaluated to decide the optimal management

    Testosterone decreases adiponectin levels in female to male transsexuals

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    Aim: To evaluate the effect of testosterone (T) on adiponectin serum levels in transsexual female patients. Methods: We measured adiponectin, leptin, luteinizing hormone and follicle stimulating hormone, T, estradiol, lipid profile, biochemical parameters and body composition in 16 transsexual female patients at baseline and after 6 months of T treatment (100 mg Testoviron Depot /10 days, i.m.). Results: Adiponectin levels were 16.9 ± 7.3 mg/mL at baseline and 13.5 ± 7.4 mg/mL at month 6 of T treatment (P < 0.05). Leptin and high-density lipoprotein cholesterol decreased significantly, whereas body mass index, waist circumference and lean body mass increased significantly after 6 months of T treatment. No changes in insulin or Homeostasis Model Assessment were detected. Conclusion: T can significantly reduce adiponectin serum levels in transsexual female patients

    Dispersion engineered As2S3 planar waveguides for broadband four-wave mixing based wavelength conversion of 40 Gb/s signals

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    We demonstrate broadband wavelength conversion of a 40 Gb/s return-to-zero signal using four-wave-mixing (FWM) in a dispersion engineered chalcogenide glass waveguide. The 6 cm long planar rib waveguide 2 μm wide was fabricated in a 0.87 μm thick film etched 350nm deep to correspond to a design where waveguide dispersion offsets the material leading to near-zero dispersion in the C-band and broadband phase matched FWM. The reduced dimensions also enhance the nonlinear coefficient to 9800 W-1km-1 at 1550 nm enabling broadband conversion in a shorter device. In this work, we demonstrate 80 nm wavelength conversions with 1.65 dB of power penalty at a bit-error rate of 10-9. Spectral measurements and simulations indicate extended broadband operation is possible

    Highly-nonlinear chalcogenide glass devices for high-speed signal processing and characterization

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    We review the latest advances in dispersion-shifted Chalcogenide waveguides enabling highly nonlinear and low dispersion planar rib circuits of centimetre length. Its performance advantages for more broadband and higher speed nonlinear signal processing are shown

    Terahertz bandwidth RF spectrum analysis of femtosecond pulses using a chalcogenide chip

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    We report the first demonstration of the use of an RF spectrum analyser with multi-terahertz bandwidth to measure the properties of femtosecond optical pulses. A low distortion and broad measurement bandwidth of 2.78 THz (nearly two orders of magnitude greater than conventional opto-electronic analyzers) was achieved by using a 6 cm long As2S3 chalcogenide waveguide designed for high Kerr nonlinearity and near zero dispersion. Measurements of pulses as short as 260 fs produced from a soliton-effect compressor reveal features not evident from the pulse’s optical spectrum. We also applied an inverse Fourier transform numerically to the captured data to re-construct a time-domain waveform that resembled pulse measurement obtained from intensity autocorrelation
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