5,316 research outputs found
On-chip integrated nanowire device platform with controllable nanogap for manipulation, capturing, and electrical characterization of nanoparticles
Cataloged from PDF version of article.We propose and demonstrate nanowire (NW) device
platforms on-chip integrated using electric-field-assisted
self-assembly. This platform integrates from nanoprobes to microprobes,
and conveniently allows for on-chip manipulation, capturing,
and electrical characterization of nanoparticles (NPs).
Synthesizing segmented (Au–Ag–Au) NWs and aligning them
across predefined microelectrode arrays under ac electric field,
we controllably form nanogaps between the self-aligned end (Au)
segments by selectively removing the middle (Ag) segments. We
precisely control and tune the size of this middle section for
nanogap formation in the synthesis process. Using electric field
across nanogaps between these nanoprobes, we capture NPs to electrically
address and probe them at the nanoscale. This approach
holds great promise for the construction of single NP devices with
electrical nanoprobe contacts
Publishing in face of the COVID-19 pandemic
Doctors around the world are desperately looking for guidance to enable them to better manage their COVID-19 patients..
Metamaterial based telemetric strain sensing in different materials
Cataloged from PDF version of article.We present telemetric sensing of surface strains on different industrial materials using split-ring-resonator based metamaterials. For wireless strain sensing, we utilize metamaterial array architectures for high sensitivity and low nonlinearity-errors in strain sensing. In this work, telemetric strain measurements in three test materials of cast polyamide, derlin and polyamide are performed by observing operating frequency shift under mechanical deformation and these data are compared with commercially-available wired strain gauges. We demonstrate that hard material (cast polyamide) showed low slope in frequency shift vs. applied load (corresponding to high Young's modulus), while soft material (polyamide) exhibited high slope (low Young's modulus). (C) 2010 Optical Society of America
Design and Realization of a Fully On-Chip High-Q Resonator at 15 GHz on Silicon
Cataloged from PDF version of article.We develop and demonstrate an on-chip resonator working at 15 GHz with a high quality factor (Q-factor) of 93.81 while only requiring a small chip size of 195 mu m x 195 mu m on Si by using our new design methodology. In our design, unlike previous approaches, we avoid the need for any external capacitance for tuning; instead, we utilize the film capacitance as the capacitor of the LC tank circuit and realize a fully on-chip resonator that shows a strong transmission dip of > 30 dB on resonance as required for telemetric-sensing applications. We present the design, theory, methodology, microfabrication, experimental characterization, and theoretical analysis of these resonators. We also demonstrate that the experimental results are in excellent agreement with the theoretical (both analytical and numerical) results. Based on our proof-of-concept demonstration, such high-Q on-chip resonators hold great promise for use in transmissive telemetric sensors
Use of evidence to support healthy public policy: a policy effectiveness-feasibility loop
Public policy plays a key role in improving population health and in the control of diseases, including non-communicable diseases.
However, an evidence-based approach to formulating healthy public policy has been difficult to implement, partly on account of barriers
that hinder integrated work between researchers and policy-makers. This paper describes a “policy effectiveness–feasibility loop” (PEFL) that
brings together epidemiological modelling, local situation analysis and option appraisal to foster collaboration between researchers and
policy-makers. Epidemiological modelling explores the determinants of trends in disease and the potential health benefits of modifying
them. Situation analysis investigates the current conceptualization of policy, the level of policy awareness and commitment among key
stakeholders, and what actually happens in practice, thereby helping to identify policy gaps. Option appraisal integrates epidemiological
modelling and situation analysis to investigate the feasibility, costs and likely health benefits of various policy options. The authors illustrate
how PEFL was used in a project to inform public policy for the prevention of cardiovascular diseases and diabetes in four parts of the eastern
Mediterranean. They conclude that PEFL may offer a useful framework for researchers and policy-makers to successfully work together to
generate evidence-based policy, and they encourage further evaluation of this approach
Microfluidic production of perfluorocarbon-alginate core-shell microparticles for ultrasound therapeutic applications
The fabrication of micrometer-sized core−shell
particles for ultrasound-triggered delivery offers a variety of
applications in medical research. In this work, we report the
design and development of a glass capillary microfluidic system
containing three concentric glass capillary tubes for the
development of core−shell particles. The setup enables the
preparation of perfluorocarbon-alginate core−shell microspheres
in a single process, avoiding the requirement for
further extensive purification steps. Core−shell microspheres
in the range of 110−130 μm are prepared and are demonstrated to be stable up to 21 days upon immersion in calcium chloride
solution or water. The mechanical stability of the particles is tested by injecting them through a 23 gauge needle into a
polyacrylamide gel to mimic the tissue matrix. The integrity of the particles is maintained after the injection process and is
disrupted after ultrasound exposure for 15 min. The results suggest that the perfluorcarbon-alginate microparticles could be a
promising system for the delivery of compounds, such as proteins, peptides, and small-molecule drugs in ultrasound-based
therapies.The authors acknowledge Gulden Camci-Unal for her help with the confocal microscope analysis. A.R.C.D. acknowledges the Fulbright Commission for the visiting scholar granted. We also acknowledge the financial support from project "Novel smart and biomimetic materials for innovative regenerative medicine approaches (RL1 - ABMR - NORTE-01-0124-FEDER-000016)" cofinanced by the North Portugal Regional Operational Programme (ON.2 - O Novo Norte) under the National Strategic Reference Framework (NSRF) through the European Regional Development Fund (ERDF) and FEDER
Determining North Atlantic meridional transport variability from pressure on the western boundary: a model investigation.
In this paper we investigate the possibility of determining North
Atlantic meridional transport variability using pressure on the western boundary, focusing on the 42degN latitude of the Halifax WAVE array. We start by
reviewing the theoretical foundations of this approach. Next we present results from a model analysis, both statistical and dynamic, that demonstrate
the feasibility of the approach. We consider how well we can quantify the meridional transport variability at 42degN given complete knowledge of bottom pressure across the basin, and to what degree this quantification is degraded by first ignoring the effect of intervening topography, and then by using only bottom pressure on the western boundary. We find that for periods of greater
than one year we can recover more than 90% of the variability of the main
overturning cell at 42degN using only the western boundary pressure, provided
we remove the depth-average boundary pressure signal. This signal arises from
a basin mode of bottom pressure variability, which has power at all timescales,
but that does not in truth have a meridional transport signal associated with
it, and from the geostrophic depth-independent compensation of the Ekman
transport. An additional benefit of the removal of the depth-average pressure is that this high-frequency Ekman signal, which is essentially noise as
far as monitoring the MOC for climatically important changes is concerned,
is clearly separated from other modes
Enhancement of wear properties of a polyether ether ketone polymer by incorporation of carbon and glass fibers
Dual functionality of conjugated polymer nanoparticles as an anticancer drug carrier and a fluorescent probe for cell imaging
Cataloged from PDF version of article.Multifunctional nanoparticles based on a green emitting, hydrophobic conjugated polymer, poly[(9,9-bis{propeny}fluorenyl-2,7-diyl)-co-(1,4- benzo-{2,1,3}-thiodiazole)] (PPFBT), that acts both as a fluorescent reporter and a matrix to accommodate an anti-cancer compound, camptothecin (CPT), were prepared, characterized and their potential as a fluorescent probe for cell imaging and as a drug delivery vehicle were evaluated via in vitro cell assays. The cell viability of human hepatocellular carcinoma cell line (Huh7) was investigated in the absence and presence of CPT with sulforhodamine B (SRB) and real-time cell electronic sensing (RT-CES) cytotoxicity assays
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