There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

Fast parallel algorithms for short-range molecular dynamics

Intermolecular And Surface Forces

The isolation and characterization of exosomes

Targeted delivery of anticancer drugs is considered to be one of the pillars of cancer treatment as it could allow for a better treatment efficiency and less adverse effects. A promising drug delivery approach is magnetic drug targeting which can be realized if a drug delivery vehicle possesses a strong magnetic moment. Here, we discuss different types of magnetic nanomaterials which can be used as magnetic drug delivery vehicles, approaches to magnetic targeted delivery as well as promising strategies for the enhancement of the imaging-guided delivery and the therapeutic action.

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Magnetic Drug Delivery: Where the Field Is Going.

Solution-phase printing of nanomaterial-based graphene inks are rapidly gaining interest for fabrication of flexible electronics. However, scalable manufacturing techniques for high-resolution printed graphene circuits are still lacking. Here, we report a patterning technique [i.e., inkjet maskless lithography (IML)] to form high-resolution, flexible, graphene films (line widths down to 20 μm) that significantly exceed the current inkjet printing resolution of graphene (line widths ∼60 μm). IML uses an inkjet printed polymer lacquer as a sacrificial pattern, viscous spin-coated graphene, and a subsequent graphene lift-off to pattern films without the need for prefabricated stencils, templates, or cleanroom technology (e.g., photolithography). Laser annealing is employed to increase conductivity on thermally sensitive, flexible substrates [polyethylene terephthalate (PET)]. Laser annealing and subsequent platinum nanoparticle deposition substantially increases the electroactive nature of graphene as illust...

High-Resolution Graphene Films for Electrochemical Sensing via Inkjet Maskless Lithography

This brief communication evaluates the cytotoxicity and targeting capability of a dry powder chemotherapeutic. Nano-in-microparticles (NIMs) are a dry powder drug delivery vehicle containing superparamagnetic iron oxide nanoparticles (SPIONs) and either doxorubicin (w/w solids) or fluorescent nanospheres (w/v during formulation; as a drug surrogate) in a lactose matrix. In vitro cytotoxicity was evaluated in A549 adenocarcinoma cells using MTS and LDH assays to assess viability and toxicity after 48 h of NIMs exposure. In vivo magnetic-field-dependent targeting of inhaled NIMs was evaluated in a healthy mouse model. Mice were endotracheally administered fluorescently labeled NIMs either as a dry powder or a liquid aerosol in the presence of an external magnet placed over the left lung. Quantification of fluorescence and iron showed a significant increase in both fluorescence intensity and iron content to the left magnetized lung. In comparison, we observed decreased targeting of fluorescent nanospheres to the left lung from an aerosolized liquid suspension, due to the dissociation of SPIONs and nanoparticles during pulmonary administration. We conclude that dry powder NIMs maintain the therapeutic cytotoxicity of doxorubicin and can be better targeted to specific regions of the lung in the presence of a magnetic field, compared to a liquid suspension.

In Vivo Pulmonary Delivery and Magnetic-Targeting of Dry Powder Nano-in-Microparticles

https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=3939&context=facpub

CIP2A immunosensor comprised of vertically-aligned carbon nanotube interdigitated electrodes towards point-of-care oral cancer screening.

Solution-phase printing of exfoliated graphene flakes is emerging as a low-cost means to create flexible electronics for numerous applications. The electrical conductivity and electrochemical reactivity of printed graphene has been shown to improve with post-print processing methods such as thermal, photonic, and laser annealing. However, to date no reports have shown the manipulation of surface wettability via post-print processing of printed graphene. Herein, we demonstrate how the energy density of a direct-pulsed laser writing (DPLW) technique can be varied to tune the hydrophobicity and electrical conductivity of the inkjet-printed graphene (IPG). Experimental results demonstrate that the DPLW process can convert the IPG surface from one that is initially hydrophilic (contact angle ∼47.7°) and electrically resistive (sheet resistance ∼21 MΩ □−1) to one that is superhydrophobic (CA ∼157.2°) and electrically conductive (sheet resistance ∼1.1 kΩ □−1). Molecular dynamic (MD) simulations reveal that both the nanoscale graphene flake orientation and surface chemistry of the IPG after DPLW processing induce these changes in surface wettability. Moreover, DPLW can be performed with IPG printed on thermally and chemically sensitive substrates such as flexible paper and polymers. Hence, the developed, flexible IPG electrodes treated with DPLW could be useful for a wide range of applications such as self-cleaning, wearable, or washable electronics.

Superhydrophobic inkjet printed flexible graphene circuits via direct-pulsed laser writing

Lipopolysaccharide (LPS) is the primary component of the outer membrane of Gram‐negative bacteria. LPS aids in protecting bacterial cells, and also defines the unique serogroups used to classify bacteria. Additionally, LPS is an endotoxin and the primary stimulator of innate immune cells in mammals, making it an ideal candidate for early detection of pathogens. However, the majority of methods for detection of LPS focus on detection of the endotoxic component of the molecule, lipid A. Since lipid A is largely conserved among bacterial species and serogroups, these detection approaches are highly nonspe‐ cific. Thus, the importance of identifying the O‐polysaccharide antigenic portion of LPS, which confers serogroup specificity, has received a great deal of attention in recent years. However, methods that are highly selective to the O‐antigens are typically less sensitive than those that target the endotoxin. Here we present a history and comparison of the sensitivity of these methods and their value for detecting bacteria in a variety of different sample types.

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Loreen R. Stromberg

Papers

High-Resolution Graphene Films for Electrochemical Sensing via Inkjet Maskless Lithography

In Vivo Pulmonary Delivery and Magnetic-Targeting of Dry Powder Nano-in-Microparticles

CIP2A immunosensor comprised of vertically-aligned carbon nanotube interdigitated electrodes towards point-of-care oral cancer screening.

Superhydrophobic inkjet printed flexible graphene circuits via direct-pulsed laser writing

Detection Methods for Lipopolysaccharides: Past and Present