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The Pigmented Lesion Assay (PLA, sensitivity 91-95%, specificity 69-91%, negative predictive value ?99%) is a commercially available, non-invasive gene expression test that helps dermatologists guide pigmented lesion management decisions and rule out melanoma. Earlier studies have demonstrated high clinical utility and no missed melanomas in a 3-6-month follow-up period. We undertook the current investigations to provide 12-month follow-up data on PLA(-) tests, and to further confirm utility. A 12-month chart review follow-up of 734 pigmented lesions that had negative PLA results from 5 US dermatology centers was performed. Thirteen of these lesions (1.8%) were biopsied in the follow-up period and submitted for histopathologic review. None of the lesions biopsied had a histopathologic diagnosis of melanoma. The test's utility was studied further in a registry (N=1575, 40 US dermatology offices, 62 participating providers), which demonstrated that 99.9% of PLA(-) lesions were clinically monitored, thereby avoiding a surgical procedure, and 96.5% of all PLA(+) lesions were appropriately biopsied, most commonly with a tangential shave. This long-term follow-up study confirms the PLA's high negative predictive value and high utility in helping guide the management of pigmented lesions to avoid unnecessary surgical procedures.

The revised version of the article corrected Figure 2. This change appears in the revised online PDF copy of this article.

Plant pathogens that are transmitted by insect vectors cause considerable damage to crops when pests or pathogens are not detected early in the season and populations are not controlled. Knowledge of pathogen prevalence in insect pest populations can aid growers in their insect pest management decisions but requires the timely dissemination of results. This process requires that specimen capture, identification, nucleic acid extraction, and molecular detection of a pathogen(s) occur alongside a platform for sharing results. The potato psyllid (Bactericera cockerelli , Sulc; Hemiptera: Triozidae) and beet leafhopper (Circulifer tenellus , Baker; Hemiptera: Cicadellidae) transmit pathogens to potato and other vegetable or seed crops each season in the northwestern United States. While the potato psyllid has been tested for pathogen occurrence for the past decade, testing of the beet leafhopper is a new endeavor and substantially increases the specimen number that must be tested by our laboratories each season. To aid in the rapid processing of individual insect specimens, we optimized and validated a new high-throughput 96-well plate nucleic acid extraction method for use in place of a standard 1.5-ml single-tube extraction method. Processing efficiency, in terms of total specimens processed over a 2-day period, improved 2.5-fold, and the cost associated with processing a single sample was nearly cut in half with this newly developed plate nucleic acid extraction method. Overall, this method has proven to be an excellent tool for the rapid testing of large numbers of small, individual insect vectors to enable timely dissemination of data on pathogen prevalence to growers. [ABSTRACT FROM AUTHOR]

Background The mainstay of diagnostic confirmation of acute Japanese encephalitis (JE) involves detection of anti-JE virus (JEV) immunoglobulin M (IgM) by enzyme-linked immunosorbent assay (ELISA). Limitations in the specificity of this test are increasingly apparent with the introduction of JEV vaccinations and the endemicity of other cross-reactive flaviviruses. Virus neutralization testing (VNT) is considered the gold standard, but it is challenging to implement and interpret. We performed a pilot study to assess IgG depletion prior to VNT for detection of anti-JEV IgM neutralizing antibodies (IgM-VNT) as compared with standard VNT. Methods We evaluated IgM-VNT in paired sera from anti-JEV IgM ELISA-positive patients (JE n=35) and negative controls of healthy flavivirus-naïve (n=10) as well as confirmed dengue (n=12) and Zika virus (n=4) patient sera. IgM-VNT was subsequently performed on single sera from additional JE patients (n=76). Results Anti-JEV IgG was detectable in admission serum of 58% of JE patients. The positive, negative and overall percentage agreement of IgM-VNT as compared with standard VNT was 100%. A total of 12/14 (86%) patient samples were unclassified by VNT and, with sufficient sample available for IgG depletion and IgG ELISA confirming depletion, were classified by IgM-VNT. IgM-VNT enabled JE case classification in 72/76 (95%) patients for whom only a single sample was available. Conclusions The novel approach has been readily adapted for high-throughput testing of single patient samples and it holds promise for incorporation into algorithms for use in reference centres. [ABSTRACT FROM AUTHOR]

Reversible addition--fragmentation chain transfer polymerization is employed here to 'allow detector-free visualization of specific DNA sequences for which dynamic polymer growth is used in signal amplification. In particular, surface-initiated polymer growth was regulated by the immobilization of chain transfer agents on the Au surface where DNA hybridization occurred. A linear polymer growth was observed as a function of the reaction time, characteristic of 'living' polymer reactions. Significant improvement in assay sensitivity was realized in comparison to the previously reported polymerization-based sensing method by enhancing polymer growth rate and reducing background noises caused by nonspecific adsorption. Direct visualization of fewer than 2,000 copies of a short oligonucleotide sequence was demonstrated in a detector-free fashion.

We report here a new DNA detection method in which polymer growth in atom transfer radical polymerization (ATRP) is used as a means to amplify detection signals. In this method, DNA hybridization and ligation reactions led to the attachment of ATRP initiators on a solid surface where specific DNA sequences were located. These initiators subsequently triggered the growth of poly(hydroxyethyl methacrylate) (PHEMA) at the end of immobilized DNA molecules and formed polymer brushes. The formation of PHEMA altered substrate opacity, rendering the corresponding spots readily distinguishable to the naked eye. A second ATRP reaction to form branched polymers on the surface drastically improved the visibility of DNA hybridization and significantly shortened the detection time. The resulting polymer film was characterized using infrared spectroscopy, ellipsometry, contact angle measurements, and atomic force microscopy. Direct visualization of 1 fmol of target DNA molecules of interest was demonstrated. A proof-of-principle experiment to detect DNA point mutation was conducted. The perfectly matched DNA targets were distinctively differentiated from those with mutations. The demonstrated capability to detect DNA mutation with direct visualization laid the groundwork for the future development of detector-free testing kits in single-nucleotide polymorphism screenings.

A consistent set of data were obtained using a combination of electrochemical NMR and computational methods to support the fact that backfolded linkages result in dendrimers that are more encapsulating yet smaller than their extended counter parts. The conclusion was made by direct comparison of sets of dendimers that differed only in the relative structural element.

The surface of poly(ethylene terephthalate) (PET) films crystallizes when exposed to a broad class of organic solvents (protic polar, aprotic polar, and non‐polar). This phenomenon leads to irreversible changes in transparency and mechanical properties. It also limits PET films and coatings in applications including electronics, medicine, packaging, and construction. This work describes a method to impart solvent resistance to the PET surface by depositing a silicate film. This coating enables many post‐functionalization options, including those that tune wettability or impart antifouling characteristics to the parent PET surface. It also endows PET surface resistance to organic solvent exposure without affecting the overall mechanical and optical properties of the PET. Additionally, the silicate layer improves the scratch resistance of PET surfaces. [ABSTRACT FROM AUTHOR]

A comparison of the heterogeneous electron-transfer rate constants of both flexible and rigid series of redox-active, iron-sulfur core dendrimers is presented. The flexible series were less effective at attenuating the rate of electron transfer than the rigid series.

We show that the aging dynamics of a strong glass former displays a strikingly simple scaling behavior, connecting the average dynamics with its fluctuations, namely, the dynamical heterogeneities. We perform molecular dynamics simulations of SiO2 with van Beest-Kramer-van Santen interactions, quenching the system from high to low temperature, and study the evolution of the system as a function of the waiting time tw measured from the instant of the quench. We find that both the aging behavior of the dynamic susceptibility χ4 and the aging behavior of the probability distribution P(fs,r) of the local incoherent intermediate scattering function fs,r can be described by simple scaling forms in terms of the global incoherent intermediate scattering function C. The scaling forms are the same that have been found to describe the aging of several fragile glass formers and that, in the case of P(fs,r), have been also predicted theoretically. A thorough study of the length scales involved highlights the importance of intermediate length scales. We also analyze directly the scaling dependence on particle type and on wavevector q and find that both the average and the fluctuations of the slow aging dynamics are controlled by a unique aging clock, which is not only independent of the wavevector q, but is also the same for O and Si atoms. [ABSTRACT FROM AUTHOR]

We show that the aging dynamics of a strong glass former displays a strikingly simple scaling behavior, connecting the average dynamics with its fluctuations, namely, the dynamical heterogeneities. We perform molecular dynamics simulations of SiO2 with van Beest-Kramer-van Santen interactions, quenching the system from high to low temperature, and study the evolution of the system as a function of the waiting time tw measured from the instant of the quench. We find that both the aging behavior of the dynamic susceptibility χ4 and the aging behavior of the probability distribution P(fs,r) of the local incoherent intermediate scattering function fs,r can be described by simple scaling forms in terms of the global incoherent intermediate scattering function C. The scaling forms are the same that have been found to describe the aging of several fragile glass formers and that, in the case of P(fs,r), have been also predicted theoretically. A thorough study of the length scales involved highlights the importance of intermediate length scales. We also analyze directly the scaling dependence on particle type and on wavevector q and find that both the average and the fluctuations of the slow aging dynamics are controlled by a unique aging clock, which is not only independent of the wavevector q, but is also the same for O and Si atoms. [ABSTRACT FROM AUTHOR]

A method for the synthesis of novel organothiol-functionalized dendrons was developed based on a straightforward reaction sequence. The modified synthetic strategy involves the preparation of triol repeat units and the first generation of the primary alcohol, [G-1]-OH,5. A convenient route was also developed for the synthesis of the protected aromatic thiol coupling unit which was utilized to couple with the dendrons.

A method for the synthesis of novel organothiol-functionalized dendrons was developed based on a straightforward reaction sequence. The modified synthetic strategy involves the preparation of triol repeat units and the first generation of the primary alcohol, [G-1]-OH,5. A convenient route was also developed for the synthesis of the protected aromatic thiol coupling unit which was utilized to couple with the dendrons.

An internal or external electric field F can drive the chemical structure, bond order afternation, and electronic structure of linear polymethine dyes from a neutral bond-alternated, polyene-like structure, through a cyanine-like structure, and ultimately to a zwitterionic (charge-separated) bond-alternated structure. As the structure evolves under the influence of F, the linear polarizability α, the first hyperpolarizability β, and the second hyperpolarizability γ are seen to be derivatives, with respect to F, of their next or order polarization (for α) or polarizability (for β and γ). These derivative relations provide a unified picture of the dependence of the polarizability and hyperpolarizabilities on the structure in linear polymethine dyes. In addition, they allow for predictions of structure-property relations of higher order hyperpolarizabilities., Since the discovery of synthetic dyes in the 1800s, chemists and physicists have been attempting to understand the relation between chemical structure, electronic structure[1-3], linear optical properties, and linear polarizability [...]

The solvent dependence of the second hyperpolarizability, γ, of a variety of unsaturated organic compounds has been measured by third harmonic generation at 1907 nanometers. iIt is seen that the measured γ is a function of solvent polarity. These solvent-dependent hyperpolarizabilities are associated with changes in molecular geometry from a highly bond-length alternated, polyene-like structure for a formyl-substituted compound in nonpolar solvents, to a cyanine-like structure, with little bond-length alternation, for a dicyanovinyl-substituted compound in polar solvents. By tuning bond-length alternation, γ can be optimized in either a positive or negative sense for polymethine dyes of a given conjugation length., The development of materials with third-rder optical nonlinearities has been the focus of much recent research[1, 2].Such materials are of interest for a variety of optical switching and processing applications. [...]

The ring opening metathesis polymerization was used to develop high molecular weight partially substituted polyacetylenes (poly-RCOT). The revocable reductive and oxidative doping mechanisms signified a shift of one electron for each 13-15 double bonds of the polymer. The electrochemistry of primarily cis poly-RCOT films was irrevocable, suggesting the existence of an electrochemical cis-trans isomerization on the initial voltammetric sweep by oxidative or reductive doping. The electrochemically doped poly-RCOT had mid-gap changes at energies of 0.8 to 0.9 eV. The dissolved polymers were electroactive over several potentials.

The synthesis of a partially substituted family of polyacetylenes from the ring-opening metathesis polymerization of monosubstituted cyclooctatetraenes is reported. The physical properties of these polyacetylene derivatives and their effects on the resulting polymer structure are also described. Results show that the synthesized polymers have high molecular weight, is highly conjugated and are generally soluble in both the cis and trans forms.

Thin Films of [n-Si/Poly-(CH.sub.3).sub.3.Si-Cyclooctatetraene:] Conducting-Polymer Solar Cells and Layered Structures ELECTRONICALLY CONDUCTIVE POLYMERS are currently of interest for their possible applications in electronics [1], nonlinear optics [2], and solar energy [...]

• Vectors of Japanese Encephalitis Virus are abundant all the year in Cambodia. • One-year study and seasonality of JEV vectors. • Effect of host presence on JEV vector abundance in pig farms and cattle house. • The most abundant vectors are Culex vishnui , Cx. gelidus and Cx. tritaeniorhynchus. The Japanese encephalitis virus (JEV) is one of the main causes of encephalitis in Asia, including Cambodia. An understanding of the interactions between JEV hosts and vectors (Diptera: Culicidae) remains rare in the context of expanding urbanization. The relative abundance, species diversity and population dynamics of potential JEV vectors were studied between August 2015 and July 2016 on a peri -urban and rural pig farm in Kandal province, Cambodia, where JEV is circulating. Five similar environments in the two farms were selected for mosquito trapping: pig farm, cattle house, river/canals, household/ponds and paddy fields. The main objective was to describe the distribution and the dynamics of the main JEV vector mosquito species. In total, 83,013 mosquitoes from 20 species were caught in rural and peri -urban areas, and 82.3% of the mosquitoes were potential JEV vector species. In peri -urban areas, Culex (Cx.) gelidus was the most abundant species, followed by Cx. vishnui subgroup and Cx. tritaeniorhynchus. In rural areas, the same species were dominant: Cx. vishnui subgroup, Cx. gelidus and Cx. tritaeniorhynchus. The vast majority of mosquitoes (95.9%) were collected in close proximity to pigs and cattle. In conclusion, JEV vectors were present at all study sites and throughout all months of the year, supporting a continuous circulation of JEV in Cambodia. [ABSTRACT FROM AUTHOR]

The degree of bond length alteration in donor/acceptor polyenes was investigated to determine its applicability to the examination of structure-property relationships for nonlinear optical chromophores. All experiments were performed both in the solid state and in solution. Results indicate that the bond length in donor/acceptor polyenes can be tuned with solvent from a polyene to a cyanine limit.

The method of synthesis of relatively organized and stable self-assembled monolayers (SAMs) of terminal acetylenes on gold, which can be used to stabilize gold nanoparticles, is described. An upright orientation of the molecules exists through some type of end-on interaction between the alkyne and substrate.

The synthesis of molecule in which thioacetate and isonitrile groups are placed at the two ends was reported. The apparent selectiveness for binding do not follow those observed by Wrighton and Whitesides in which separate, thiol-containing and isonitrile-containing molecules competed for a bare metal substrate.

The way in which the type of initial self-assembled monolayers (SAMs) on the surface influences the replacement lithography process is determined. Thus, it is concluded that the degree of the displacement at a given bias likely correlates with the relative ease of the desorption step and the bias of replacement correlates with the electrochemical, reductive desorption potential of the SAM.

Time-resolved femtosecond fluorescence, florescence anisotropy dynamics and temperature dependent steady state spectral studies of a second-generation homogeneous phenylacetylene dendrimer are reported. Time-resolved fluorescence results suggest delocalization of the excitation energy in the excited states.