2-[4-(Diethyl­amino)­benzyl­idene]malono­nitrile

In the title compound, C14H15N3, the diethyl­amino N atom, benzene ring, olefinic bond and cyano groups form an extended conjugated system, making the mol­ecule nearly planar: the dihedral angle between the benzene ring and the best plane throught the cyano groups is 4.93 (10)°, while the dihedral angle between the benzene ring and the plane through the diethyl­amino N atom and the two attached ethyl C atoms is 9.51 (14)°. In the crystal, inter­molecular C—H⋯π inter­actions stabilize the packing

Non-Hermitian guided modes and exceptional points using loss-free negative-index materials

We analyze the guided modes in coupled waveguides made of negative-index materials without gain or loss. We show that it supports non-Hermitian phenomenon on the existence of guided mode versus geometric parameters of the structure. The non-Hermitian effect is different from parity-time (PT) symmetry, and can be explained by a simple coupled-mode theory with an anti-PT symmetry. The existence of exceptional points and slow-light effect are discussed. This work highlights the potential of loss-free negative-index materials in the study of non-Hermitian optics

Higher-order exceptional points in loss-free waveguide arrays with negative-index materials

Negative-index materials (NIMs) are shown to support optical anti-parity-time (anti-PT) symmetry even when they are lossless. Here we prove the feasibility in achieving higher-order exceptional points (EPs) in loss-free waveguide arrays by utilizing the anti-$\mathcal{PT}$ symmetry induced by NIM. Numerical simulation about a third-order EP fits well with the coupled-mode theory. A scheme of achieving fourth-order EPs is also discussed. This work highlights the potential of loss-free NIMs in the study of non-Hermitian optics

Preparation of berberine hydrochloride long-circulating liposomes by ionophore A23187-mediated ZnSO4 gradient method

AbstractThe aim of the study was to prepare berberine hydrochloride long-circulating liposomes and optimize the formulation and process parameters, and investigate the influence of different factors on the encapsulation efficiency. Berberine hydrochloride liposomes were prepared in response to a transmembrane ion gradient that was established by ionophore A23187. Free and liposomal drug were separated by cation exchange resin, and then the amount of intraliposomal berberine hydrochloride was determined by UV spectrophotometry. The optimized encapsulation efficiency of berberine hydrochloride liposomes was 94.3% ± 2.1% when the drug-to-lipid ratio was 1:20, and the mean diameter was 146.9 nm ± 3.2 nm. As a result, the ionophore A23187-mediated ZnSO4 gradient method was suitable for the preparation of berberine hydrochloride liposomes that we could get the desired encapsulation efficiency and drug loading

Infant's sex, birth control policy and postpartum well-being: a prospective cohort study in Shanghai, China

Objectives: The Chinese government loosed its birth control policy and allowed the parents to have the second child if both of the parent were from one-child family from 2001. We explore the association between infant’s sex and mother’s postpartum well-being, which may be moderated by birth control policy status in China. Setting and Participants: We conducted a prospective cohort study in Shanghai City, one of the largest cities in China. A total number of 1730 childbearing women from 8 obstetric hospitals across Shanghai were included in the study at baseline, with 1503 women completing the survey 7 days postpartum in 2013. Measures: The General Well-Being Schedule (GWBS) was used to assess maternal well-being at baseline and follow-up investigation in the study. Women’s demographic, clinical characteristic, and well-being were measured at baseline. The maternal satisfaction and postpartum well-being were assessed in the follow-up survey. Results The results of multivariable linear regression analyses showed that women who gave birth to male infants were positively associated with the total score of maternal well-being, when the participated hospitals, maternal well-being at baseline, the socio-demographic characteristic, maternal and infant’s health outcome were added to the adjustments (β=1.462, P0.05). The results of multiple logistic regression model showed that having a male infant was a protective factor of ‘positive well-being’ (OR=0.622, P0.05). Conclusions: Our results emphasize the importance in conducting intervention to increase the general well-being, especially for those with a female infant in a son preference society such as China, and enhance the necessity of sustainability of newly relaxed two-child policy which allows more couples to have the second child in China

Characterization of Cu3SbS3 thin films grown by thermally diffusing Cu2S and Sb2S3 layers

Copper antimony sulphide (Cu3SbS3) with a p-type conductivity and optical band gaps in the range of 1.38 to 1.84 eV is considered to be a promising solar harvesting material with non-toxic and economical elements. In this study, we reported the fabrication of Cu3SbS3 thin films using successive thermal evaporation of Cu2S and Sb2S3 layers followed by annealing in an argon atmosphere at a temperature range of 300-375°C. The structural and optical properties of the as-deposited and annealed films were investigated. The annealed films notably show the crystalline phase of the Cu3SbS3, identified from the X-ray diffraction analysis and endorsed by the Raman analysis as well. Whereas their chemical state of the constituent elements was characterized with X-ray photoelectron spectroscopy. The measured highest resistivity of the annealed film was found to be ~0.2 Ω-cm. Hence, our obtained results for the fabricated Cu3SbS3 thin films bring to light that Cu3SbS3would be a good absorber layer in solar cells due to their low resistivity, a higher value of the optical absorption coefficient (~105 cm-1), the low transmittance (<5%) and an optical direct band gap of 1.6 eV in the visible range of the solar spectrum

Slippery liquid-infused porous surfaces and droplet transportation by surface acoustic waves

On a solid surface a droplet of liquid will stick due to the capillary adhesion and this causes low droplet mobility. To reduce contact line pinning, surface chemistry can be coupled to micro- and/or nano-structures to create superhydrophobic surfaces on which a droplet balls-up into an almost spherical shape thus minimising contact area. Recent progress in soft matter has now led to alternative lubricant impregnated surfaces capable of almost zero contact line pinning and high droplet mobility without causing droplets to ball-up and minimize contact area. Here we report a new approach to Surface Acoustic Wave (SAW) actuated droplet transportation enabled using such a surface. These surfaces maintain the contact area required for efficient energy and momentum transfer of the wave energy into the droplet, whilst achieving high droplet mobility and large footprint, therefore reducing the threshold power required to induce droplet motion. In our approach we used a slippery layer of lubricating oil infused into a self-assembled porous hydrophobic layer, which is significantly thinner than the SAW wavelength and so avoided damping of the wave. A significant reduction (up to 85%) in the threshold power for droplet transportation was found compared to that using a conventional surface treatment method. Moreover, unlike droplets on superhydrophobic surfaces, where interaction with the SAW induced a transition from a Cassie–Baxter state to a Wenzel state, the droplets on our liquid impregnated surfaces remained in a mobile state after interaction with the SAW

Integrating microfluidics and biosensing on a single flexible acoustic device using hybrid modes

Integration of microfluidics and biosensing functionalities on a single device holds promise in continuous health monitoring and disease diagnosis for point-of-care applications. However, the required functions of fluid handling and biomolecular sensing usually arise from different actuation mechanisms. In this work, we demonstrate that a single acoustofluidic device, based on a flexible thin film platform, is able to generate hybrid waves modes, which can be used for fluidic actuation (Lamb waves) and biosensing (thickness shear waves). On this integrated platform, we show multiple and sequential functions of mixing, transport and disposal of liquid volumes using Lamb waves, whilst the thickness bulk shear waves allow us to sense the chemotherapeutic Imatinib, using an aptamer-based strategy, as would be required for therapy monitoring. Upon binding, the conformation of the aptamer results in a change in coupled mass, which has been detected. This platform architecture has the potential to generate a wide range of simple sample-to-answer biosensing acoustofluidic devices

New dual-mode orthogonal tunable fluorescence systems based on cucurbit[8]uril: White light, 3D printing, and anti-counterfeit applications

In this work, we have utilized a supramolecular approach to control emission, and generate white light and have applied the system to both 3D printing and counterfeiting applications. In particular, we report two new dual-mode orthogonal tunable fluorescence systems, A and B. System A is based on the fluorescent dyes perylene diimide (PDI-C6) and 7-hydroxycoumarin, which are incorporated into the main guest system, namely cucurbit[8]uril (Q[8]). This system can provide bright white emission and proved to be adaptable, whereby the emission can be easily changed via temperature control; a smart temperature control switch in the range of 30 °C to 100 °C was developed. System B is based on quinine sulfate with PDI-C6 and Q[8], and this system can provide white emission over a wide concentration range and it was applied to LED lamps. Such white emission also performs well in polymeric matrices and can be utilized for 3D printing, whilst solutions can be used for more practical applications, for example as anti-counterfeiting materials