Genetically engineered plasmonic nanoarrays

In the present Letter, we demonstrate how the design of metallic nanoparticle arrays with large electric field enhancement can be performed using the basic paradigm of engineering, namely the optimization of a well-defined objective function. Such optimization is carried out by coupling a genetic algorithm with the analytical multiparticle Mie theory. General design criteria for best enhancement of electric fields are obtained, unveiling the fundamental interplay between the near-field plasmonic and radiative photonic coupling. Our optimization approach is experimentally validated by surface-enhanced Raman scattering measurements, which demonstrate how genetically optimized arrays, fabricated using electron beam lithography, lead to order of ten improvement of Raman enhancement over nanoparticle dimer antennas, and order of one hundred improvement over optimal nanoparticle gratings. A rigorous design of nanoparticle arrays with optimal field enhancement is essential to the engineering of numerous nanoscale optical devices such as plasmon-enhanced biosensors, photodetectors, light sources and more efficient nonlinear optical elements for on chip integration.     

Direct evidence of phospholipids in gecko footprints and spatula–substrate contact interface detected using surface-sensitive spectroscopy

Observers ranging from Aristotle to young children have long marvelled at the ability of geckos to cling to walls and ceilings. Detailed studies have revealed that geckos are ‘sticky’ without the use of glue or suction devices. Instead, a gecko''s stickiness derives from van der Waals interactions between proteinaceous hairs called setae and substrate. Here, we present surprising evidence that although geckos do not use glue, a residue is transferred on surfaces as they walk—geckos leave footprints. Using matrix-free nano-assisted laser desorption-ionization mass spectrometry, we identified the residue as phospholipids with phosphocholine head groups. Moreover, interface-sensitive sum-frequency generation spectroscopy revealed predominantly hydrophobic methyl and methylene groups and the complete absence of water at the contact interface between a gecko toe pad and the substrate. The presence of lipids has never been considered in current models of gecko adhesion. Our analysis of gecko footprints and the toe pad–substrate interface has significant consequences for models of gecko adhesion and by extension, the design of synthetic mimics.     

Evaluation of zinc, cadmium and lead isotope fractionation during smelting and refining

To evaluate metallurgical processing as a source of Zn and Cd isotopic fractionation and to potentially trace their distribution in the environment, high-precision MC-ICP-MS Zn, Cd and Pb isotope ratio measurements were made for samples from the integrated Zn-Pb smelting and refining complex in Trail, B.C., Canada. Significant fractionation of Zn and Cd isotopes during processing of ZnS and PbS ore concentrates is demonstrated by the total variation in δ^66/64Zn and δ^114/110Cd values of 0.42‰ and 1.04‰, respectively, among all smelter samples.No significant difference is observed between the isotopic compositions of the Zn ore concentrates (δ^66/64Zn = 0.09 to 0.17‰; δ^114/110Cd = − 0.13 to 0.18‰) and the roasting product, calcine (δ^66/64Zn = 0.17‰; δ^114/110Cd = 0.05‰), due to ∼ 100% recovery from roasting. The overall Zn recovery from metallurgical processing is ∼ 98%, thus the refined Zn metal (δ^66/64Zn = 0.22‰) is not significantly fractionated relative to the starting materials despite significantly fractionated fume (δ^66/64Zn = 0.43‰) and effluent (δ^66/64Zn = 0.41 to 0.51‰). Calculated Cd recovery from metallurgical processing is 72-92%, with the majority of the unrecovered Cd lost during Pb operations (δ^114/110Cd = − 0.38‰). The refined Cd metal is heavy (δ^114/110Cd = 0.39 to 0.52‰) relative to the starting materials. In addition, significant fractionation of Cd isotopes is evidenced by the relatively light and heavy isotopic compositions of the fume (δ^114/110Cd = − 0.52‰) and effluent (δ^114/110Cd = 0.31 to 0.46‰). In contrast to Zn and Cd, Pb isotopes are homogenized by mixing during processing. The total variation observed in the Pb isotopic compositions of smelter samples is attributed to mixing of ore sources with different radiogenic signatures.     

A Combination of Chemotherapy and Oncolytic Virotherapy Sensitizes Colorectal Adenocarcinoma to Immune Checkpoint Inhibitors in a cDC1-Dependent Manner

Immune checkpoint therapy has shown great promise in the treatment of cancers with a high mutational burden, such as mismatch repair-deficient colorectal carcinoma (dMMR CRC). However, many patients fail to respond to immune checkpoint therapy. Using a mouse model of dMMR CRC, we demonstrated that tumors can be further sensitized to immune checkpoint therapy by using a combination of low-dose chemotherapy and oncolytic HSV-1. This combination induced the infiltration of CD8⁺ and CD4⁺ T cells into the tumor and the upregulation of gene signatures associated with the chemoattraction of myeloid cell subsets. When combined with immune checkpoint therapy, the combination promoted the infiltration of activated type 1 conventional dendritic cells (cDC1s) into the tumor. Furthermore, we found this combination strategy to be dependent on cDC1s, and its therapeutic efficacy to be abrogated in cDC1-deficient Batf3^−/− mice. Thus, we demonstrated that the adjuvanticity of dMMR CRCs can be improved by combining low-dose chemotherapy and oncolytic HSV-1 in a cDC1-dependent manner.     

The effect of collision pulse properties on seven proposed whiplash injury criteria

Recent epidemiological and biomechanical studies have suggested that whiplash injury is related to a vehicle's average acceleration rather than its speed change during a rear-end collision. To further explore this phenomenon, the effect of various kinematic properties of the collision pulse on seven proposed whiplash injury criteria was quantified. A BioRID II rear-impact dummy was seated on a programmable sled and exposed six times to each of 15 different collision pulses. Five properties of the collision pulse were varied: peak acceleration (1.3-4.4 g), speed change (3-11 km/h), duration (52-180 ms), displacement (2-26 cm) and shape (square, sine and triangular). Linear and angular accelerations and displacements of the head, and linear accelerations of the T1 and pelvis were measured in the sagittal-plane. Upper neck loads in the sagittal-plane were also measured. Variations within the proposed injury criteria between the different pulses were compared using analyses of variance. Six criteria--peak upper neck shear force, peak upper neck moment, peak retraction, the neck injury criterion (NIC) and two normalized neck injury criteria (Nij and Nkm)--exhibited graded responses that were most sensitive to the average acceleration of the collision pulse. Peak extension angle between the head and T1 decreased with both increasing speed change and peak acceleration, and was, therefore, deemed unsuitable as a whiplash injury criterion for the BioRID dummy. Of the seven criteria, Nij and Nkm were best able to distinguish between the 15 pulses. If the six graded injury criteria are related to the risk of whiplash injury, then the results of this study indicate that the risk of whiplash injury can be reduced by bumper and seat designs that prolong the collision pulse and thereby reduce the average vehicle and occupant accelerations for a given speed change.     

Children's responses to same- and other-gender peers: An experimental investigation with 8-, 10-, and 12-year-olds.

This research compared how participants in the age range of middle childhood (N?=?565, approximate ages 8, 10, and 12 years) responded to provocation by a same- or an other-gender peer. In a laboratory play session, participants were provoked in two ways: by losing at a computer game and by being teased by a confederate actor. Immediately following the provoking play session, participants were interviewed about their perceptions of the provoking peer, emotional responses, coping strategies, and social goals. For both the baseline and provocation periods, observational data indicated that facial, verbal, and gestural responses to an other-gender peer were more negative than to a same-gender peer. With other-gender partners, participants reported liking the peer less, trying less to get along with the provocateur, and coping with the provocation by trying to play better rather than by verbally confronting the actor. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of bitterness, roughness, PROP taster status, and fungiform papillae density on bread acceptance

The purpose of this study was to determine how bitterness, roughness, color, perceived 6-n-propylthiouracil (PROP) intensity, and fungiform papillae density affect bread liking. To accomplish this, 78 subjects rated their liking for bread samples that were manipulated to vary independently in bitterness (provided by added wheat germ extract), roughness (provided by added bleached bran), and darkness (provided by added caramel color). The bitterness from added germ extract decreased bread liking. The roughness from the bleached bran increased bread liking; this increase was larger for subjects with higher fungiform papillae densities and was larger for subjects less sensitive to PROP.Added color decreased liking for subjects who preferred refined bread, but it increased liking for subjects who preferred whole wheat bread.     

Plasmids for C‐terminal tagging in Saccharomyces cerevisiae that contain improved GFP proteins,Envy and Ivy

Green fluorescent protein (GFP) has become an invaluable tool in biological research. Many GFP variants have been created that differ in brightness, photostability, and folding robustness. We have created two hybrid GFP variants, Envy and Ivy, which we placed in a vector for the C‐terminal tagging of yeast proteins by PCR‐mediated recombination. The Envy GFP variant combines mutations found in the robustly folding SuperfolderGFP and GFPγ, while the Ivy GFP variant is a hybrid of GFPγ and the yellow‐green GFP variant, Clover. We compared Envy and Ivy to EGFP, SuperfolderGFP and GFPγ and found that Envy is brighter than the other GFP variants at both 30°C and 37°C, while Ivy is the most photostable. Envy and Ivy are recognized by a commonly used anti‐GFP antibody, and both variants can be immunoprecipitated using the GFP TRAP Camelidae antibody nanotrap technology. Because Envy is brighter than the other GFP variants and is as photostable as GFPγ, we suggest that Envy should be the preferred GFP variant, while Ivy may be used in cases where photostability is of the utmost importance. The GenBank Accession No. for Envy is KM891731, for Ivy is KM891732 and for the yeast optimized GFPγ described in this paper is KM891733. Copyright © 2015 John Wiley & Sons, Ltd.     

Direct dry film optical bonding ‐ A low‐cost,robust, and scalable display lamination technology

Abstract— A robust, repeatable, low‐cost lamination process that utilizes pressure‐sensitive adhesive (PSA) to directly bond substrates to displays, such as LC, OLED, plasma, and electrophoretic displays, has been developed. These substrates can vary in intent and serve as protective covers, reflection mitigation, heaters, filters, touch screens, environmental barriers, etc. The resultant assembly is very rugged (shock, impact, and vibration resistant), while maximizing optical performance. This paper briefly describes the traditional liquid bonding technologies and compares them to dry‐film bonding. A section of the paper focuses on the enhanced optical and environmental performances of dry‐film bonded displays. This paper may also serve as a brief review of optical‐bonding technologies.     

Biosynthesis of the Fluorinated Natural Product Nucleocidin in Streptomyces calvus Is Dependent on the bldA‐Specified Leu‐tRNAUUA Molecule

Nucleocidin is one of the very few natural products known to contain fluorine. Mysteriously, the nucleocidin producer Streptomyces calvus ATCC 13382 has not been observed to synthesize the compound since its discovery in 1956. Here, we report that complementation of S. calvus ATCC 13382 with a functional bldA‐encoded Leu‐tRNA^UUA molecule restores the production of nucleocidin. Nucleocidin was detected in culture extracts by ¹⁹F NMR spectroscopy, HPLC‐ESI‐MS, and HPLC‐continuum source molecular absorption spectroscopy for fluorine‐specific detection. The molecule was purified from a large‐scale culture and definitively characterized by NMR spectroscopy and high‐resolution MS. The nucleocidin biosynthetic gene cluster was identified by the presence of genes encoding the 5′‐O‐sulfamate moiety and confirmed by gene disruption. Two of the genes within the nucleocidin biosynthetic gene cluster contain TTA codons, thus explaining the dependence on bldA and resolving a 60‐year‐old mystery.