A 3D-printed microfluidic-enabled hollow microneedle architecture for transdermal drug delivery.

Embedding microfluidic architectures with microneedles enables fluid management capabilities that present new degrees of freedom for transdermal drug delivery. To this end, fabrication schemes that can simultaneously create and integrate complex millimeter/centimeter-long microfluidic structures and micrometer-scale microneedle features are necessary. Accordingly, three-dimensional (3D) printing techniques are suitable candidates because they allow the rapid realization of customizable yet intricate microfluidic and microneedle features. However, previously reported 3D-printing approaches utilized costly instrumentation that lacked the desired versatility to print both features in a single step and the throughput to render components within distinct length-scales. Here, for the first time in literature, we devise a fabrication scheme to create hollow microneedles interfaced with microfluidic structures in a single step. Our method utilizes stereolithography 3D-printing and pushes its boundaries (achieving print resolutions below the full width half maximum laser spot size resolution) to create complex architectures with lower cost and higher print speed and throughput than previously reported methods. To demonstrate a potential application, a microfluidic-enabled microneedle architecture was printed to render hydrodynamic mixing and transdermal drug delivery within a single device. The presented architectures can be adopted in future biomedical devices to facilitate new modes of operations for transdermal drug delivery applications such as combinational therapy for preclinical testing of biologic treatments

Design of the iLocater Acquisition Camera Demonstration System

Existing planet-finding spectrometers are limited by systematic errors that result from their seeing-limited design. Of particular concern is the use of multi-mode fibers (MMFs), which introduce modal noise and accept significant amounts of background radiation from the sky. We present the design of a single-mode fiber-based acquisition camera for a diffraction-limited spectrometer named "iLocater." By using the "extreme" adaptive optics (AO) system of the Large Binocular Telescope (LBT), iLocater will overcome the limitations that prevent Doppler instruments from reaching their full potential, allowing precise radial velocity (RV) measurements of terrestrial planets around nearby bright stars. The instrument presented in this paper, which we refer to as the acquisition camera "demonstration system," will measure on-sky single-mode fiber (SMF) coupling efficiency using one of the 8.4m primaries of the LBT in fall 2015

Rotation of hydrogen molecules during the dissociative adsorption on the Mg(0001) surface: A first-principles study

Using first-principles calculations, we systematically study the potential energy surfaces and dissociation processes of the hydrogen molecule on the Mg(0001) surface. It is found that during the dissociative adsorption process with the minimum energy barrier, the hydrogen molecule firstly orients perpendicular, and then rotates to be parallel to the surface. It is also found that the orientation of the hydrogen molecule at the transition state is neither perpendicular nor parallel to the surface. Most importantly, we find that the rotation causes a reduction of the calculated dissociation energy barrier for the hydrogen molecule. The underlying electronic reasons for the rotation of the hydrogen molecule is also discussed in our paper.Comment: 14 pages, 4 figure

Unpaid carers of people with dementia and information communication technology: use, impact and ideas for the future

Objectives Several 100,000s of people living with dementia in the UK are cared for at home by a spouse or relative. Few studies have considered the ICT needs and experiences of unpaid carers. This study explores the types of ICT unpaid carers use, the ways they use ICT, the impact of ICT-use, and their ideas for how ICT could be more supportive of their role as a carer. Methods Six focus groups with 32 unpaid carers of people living with dementia discussed their experiences of – and barriers to – using ICT. Transcripts were analysed thematically according to three types of ICT (mainstream, accessible and formal) and five functions (supporting domestic tasks, care management, monitoring, communication and information and education). Results Participants predominantly used mainstream ICT devices such as laptops and smartphones and internet-enabled applications including videoconferencing and social media platforms to support their daily activities and assist them in their caring role. A few participants discussed using accessible devices such as memory clocks and formal telecare and care-phone services for care management and monitoring functions. Participants’ ideas for improvements centred on personalised communication applications that facilitate remote interactions and promote persons living with dementia’s independence. Others expressed concerns about the growing need to use ICT to access formal care services and the inadequacy of the ICT infrastructure in some care homes. Conclusions Unpaid carers mostly turn to readily available mainstream ICT to support their personal and care activities. Further research is required to understand the social impact of the increasing reliance of ICT across health, social and residential care service sectors. Improved cooperation between unpaid carers, technology developers and care services providers could align ICT development to the needs and experiences of families living with dementia and assist unpaid carers with identifying ICTs that optimally support their personal circumstances

Unpaid carers of people with dementia and ICT: use, impact and ideas for the future

Objectives: Several 100,000s of people living with dementia in the UK are cared for at home by a spouse or relative. Few studies have considered the ICT needs and experiences of unpaid carers. This study explores the types of ICT unpaid carers use, the ways they use ICT, the impact of ICT-use, and their ideas for how ICT could be more supportive of their role as a carer. Methods: Six focus groups with 32 unpaid carers of people living with dementia discussed their experiences of – and barriers to – using ICT. Transcripts were analysed thematically according to three types of ICT (mainstream, accessible and formal) and five functions (supporting domestic tasks, care management, monitoring, communication and information and education). Results: Participants predominantly used mainstream ICT devices such as laptops and smartphones and internet-enabled applications including videoconferencing and social media platforms to support their daily activities and assist them in their caring role. A few participants discussed using accessible devices such as memory clocks and formal telecare and care-phone services for care management and monitoring functions. Participants’ ideas for improvements centred on personalised communication applications that facilitate remote interactions and promote persons living with dementia’s independence. Others expressed concerns about the growing need to use ICT to access formal care services and the inadequacy of the ICT infrastructure in some care homes. Conclusions: Unpaid carers mostly turn to readily available mainstream ICT to support their personal and care activities. Further research is required to understand the social impact of the increasing reliance of ICT across health, social and residential care service sectors. Improved cooperation between unpaid carers, technology developers and care services providers could align ICT development to the needs and experiences of families living with dementia and assist unpaid carers with identifying ICTs that optimally support their personal circumstances

Unified triminimal parametrizations of quark and lepton mixing matrices

We present a detailed study on triminimal parametrizations of quark and lepton mixing matrices with different basis matrices. We start with a general discussion on the triminimal expansion of the mixing matrix and on possible unified quark and lepton parametrization using quark-lepton complementarity (QLC). We then consider several interesting basis matrices and compare the triminimal parametrizations with the Wolfenstein-like parametrizations. The usual Wolfenstein parametrization for quark mixing is a triminimal expansion around the unit matrix as the basis. The corresponding QLC lepton mixing matrix is a triminimal expansion around the bimaximal basis. Current neutrino oscillation data show that the lepton mixing matrix is very well represented by the tri-bimaximal mixing. It is natural to take it as an expanding basis. The corresponding zeroth order basis for quark mixing in this case makes the triminimal expansion converge much faster than the usual Wolfenstein parametrization. The triminimal expansion based on tri-bimaximal mixing can be converted to the Wolfenstein-like parametrizations discussed in the literature. We thus have a unified description between different kinds of parametrizations for quark and lepton sectors: the standard parametrizations, the Wolfenstein-like parametrizations, and the triminimal parametrizations.Comment: 14 latex pages, no figure, to appear in PR

3D Printed Tubular Scaffolds with Massively Tailorable Mechanical Behavior

Melt electrowriting (MEW) is a promising additive manufacturing technique for tissue scaffold biofabrication. Successful application of MEW scaffolds requires strictly controlled mechanical behavior. This requires scaffold geometry be optimized to match native tissue properties while simultaneously supporting cell attachment and proliferation. The objective of this work is to investigate how geometric properties can be exploited to massively tailor the mechanical behavior of tubular crosshatch scaffolds. An experimentally validated finite element (FE) model is developed and 441 scaffold geometries are investigated under tension, compression, bending, and radial loading. A range of pore areas (4–150 mm2) and pore angles (11°–134°) are investigated. It is found that scaffold mechanical behavior is massively tunable through the control of these simple geometric parameters. Across the ranges investigated, scaffold stiffness varies by a factor of 294× for tension, 204× for compression, 231× for bending, and 124× for radial loading. Further, it is discussed how these geometric parameters can be simultaneously tuned for different biomimetic material applications. This work provides critical insights into scaffold design to achieve biomimetic mechanical behavior and provides an important tool in the development of biomimetic tissue engineered constructs

Airways hyperresponsiveness to different inhaled combination therapies in adolescent asthmatics

Local electrical characterization has wide spectrum of applications in various areas. However, there are a number of difficulties that hinder the precise measurement of local electrical properties of samples, particularly those within nano-scale spatial resolution. Inspired by these challenges, we developed a nano-robot enabled electrical characterization system that can be utilized to pinpoint the local electrical properties of materials, devices, and bioentities with high spatial and electrical resolution. This system consists of an electrical characterization unit and a nano-robot with an augment reality system, which was developed from a traditional atomic force microscopy (AFM). The augment reality system provides real-time visual feedback. The real-time visual display integrated with the real-time force feedback from the nano-robot allows a precise control of the position and force of the AFM tips towards samples, which are significant for the sensitivity of local electrical measurement. The system design and implementation are presented in the paper. Experiments were carried out to study the local conductance of a multi-wall carbon nanotube (MWCNT), demonstrating the effectiveness of this system. © 2012 IEEE.Link_to_subscribed_fulltex

WD+RG systems as the progenitors of Type Ia supernovae

Type Ia supernovae (SNe Ia) play an important role in the study of cosmic evolution, especially in cosmology. There are several progenitor models for SNe Ia proposed in the past years. In this paper, by considering the effect of accretion disk instability on the evolution of white dwarf (WD) binaries, we performed detailed binary evolution calculations for the WD + red-giant (RG) channel of SNe Ia, in which a carbon-oxygen WD accretes material from a RG star to increase its mass to the Chandrasekhar mass limit. According to these calculations, we mapped out the initial and final parameters for SNe Ia in the orbital period--secondary mass plane for various WD masses for this channel. We discussed the influence of the variation of the duty cycle value on the regions for producing SNe Ia. Similar to previous studies, this work also indicates that the long-period dwarf novae offer a possible ways for producing SNe Ia. Meanwhile, we find that the surviving companion stars from this channel have a low mass after SN explosion, which may provide a means for the formation of the population of single low-mass WDs (<0.45Msun).Comment: 5 pages, 3 figure

Dissociation of hydrogen molecules on the clean and hydrogen-preadsorbed Be(0001) surface

Using first-principles calculations, we systematically study the potential energy surfaces and dissociation processes for hydrogen molecules on the clean and hydrogen-preadsorbed Be(0001) surfaces. It is found that the most energetically favored dissociation channel for H2 molecules on the clean Be surface is at the surface top site, with the minimum energy barrier of 0.75 eV. It is further found that after dissociation, hydrogen atoms do not like to cluster with each other, as well as to penetrate into subsurface sites. For the hydrogen-preadsorbed Be(0001) surface, the smallest dissociation energy barrier for H2 molecules is found to be 0.50 eV, which is smaller than the dissociation energy barrier on a clean Be(0001) surface. The critical dependence of the dissociation energy barriers for H2 molecules on their horizontal distances from the preadsorbed hydrogen atom is revealed. Our studies well describe the adsorption behaviors of hydrogen on the Be(0001) surface.Comment: 17 pages, 9 figure