Upconversion manipulation by local electromagnetic field

Publication date: Available online 15 November 2017
Source:Nano Today
Author(s): Wen Xu, Xu Chen, Hongwei Song
Rare earth doped upconversion nanocrystals (RE-UCNCs) have attracted extensive interests owing to their unique physical properties and great potential applications in bio-application, photonic and photoelectric devices etc. Although UCNCs open doors to a wide range of new opportunities, they are confronting with some difficulties and one of the fatal problems is their low upconvsersion luminescent strength/efficiency. To date, various methods have been explored to solving this significant issue. Totally to say, the methods can be classified into two aspects, the traditional size, structure, surface and crystal field controls of the UCNCs, and the novel local electromagnetic field modulation surrounding the UCNCs. The local electromagnetic field modulation on UCNCs is a powerful strategy to enhance the strength/efficiency of UCNCs, reporting enhancement from several times up to four orders in short times. The timely and concise summary on the previous literatures is significant for more rapid and formulated development of this field. This review is aimed at offering a comprehensive framework for metal/semiconductor plasmon-induced and photonic crystal effect induced upconversion enhancement. Differing from the other review articles, we first introduced the generation principle of localized electromagnetic field in metal/semiconductor nanostructure/photonic crystals, and their general interaction rules with various emitters. Then, we summed up the recent published works on the local field modulation-induced upconversion enhancement, on emphasis we did our best to discover the generality of obtaining highly improved photoluminescence for any emitters and the personality of realizing highly improved upconversion enhancement. We further prospected the future development in this attractive field based on the previous theoretical and experimental results and the requirement of application. The marriage of upconversion with nanophotonic could explore a novel frontier in photonics that potentially spawn many exciting new fields.

Graphical abstract

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High-sensitivity molecular sensing using plasmonic nanocube chains in classical and quantum coupling regimes

Publication date: Available online 15 November 2017
Source:Nano Today
Author(s): Nasrin Hooshmand, Hamed Shams Mousavi, Sajanlal R. Panikkanvalappil, Ali Adibi, Mostafa A. El-Sayed
One-dimensional plasmonic nanoparticle arrays have intriguing optical properties that can be utilized in a number of applications, including molecular sensing. In this paper, firstly, we studied the plasmonic coupling behavior in chains of gold and silver plasmonic nanocubes of 21nm edge length arranged in both face-to-face and edge-to-edge configurations at large separation distance (8.5nm), where the classical electromagnetic coupling is dominant. Interestingly, an increase in the sensitivity factor was observed when increasing the number of nanocubes in the chain and by orienting them in edge-to-edge configuration, with a few exceptions. Additionally, linear chains of edge-to-edge and face-to-face assembled gold nanocube with sub-nanometer interparticle distances (0.2nm), where the effect of tunneling-induced charge transfer plasmons (tCTPs) becomes significant, was studied using a quantum-corrected model. In comparison to the face-to-face orientation, the changes in optical properties were more prominent in the edge-to-edge configuration. Our results suggest that plasmonic coupling in linearly assembled nanoparticles becomes extremely important at sub-nanometer interparticle distances. It can significantly modify the optical properties of the nanocubes chains, especially spectral line shape and electric-field distribution, which might help designing more advanced sensing devices for chemical and bio-sensing applications.

Graphical abstract

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Nucleus accumbens core lesions induce sub-optimal choice and reduce sensitivity to magnitude and delay in impulsive choice tasks

Publication date: 26 February 2018
Source:Behavioural Brain Research, Volume 339
Author(s): Catherine C. Steele, Jennifer R. Peterson, Andrew T. Marshall, Sarah L. Stuebing, Kimberly Kirkpatrick
The nucleus accumbens core (NAc) has long been recognized as an important contributor to the computation of reward value that is critical for impulsive choice behavior. Impulsive choice refers to choosing a smaller-sooner (SS) over a larger-later (LL) reward when the LL is more optimal in terms of the rate of reward delivery. Two experiments examined the role of the NAc in impulsive choice and its component processes of delay and magnitude processing. Experiment 1 delivered an impulsive choice task with manipulations of LL reward magnitude, followed by a reward magnitude discrimination task. Experiment 2 tested impulsive choice under manipulations of LL delay, followed by temporal bisection and progressive interval tasks. NAc lesions, in comparison to sham control lesions, produced suboptimal preferences that resulted in lower reward earning rates, and led to reduced sensitivity to magnitude and delay within the impulsive choice task. The secondary tasks revealed intact reward magnitude and delay discrimination abilities, but the lesion rats persisted in responding more as the progressive interval increased during the session. The results suggest that the NAc is most critical for demonstrating good sensitivity to magnitude and delay, and adjusting behavior accordingly. Ultimately, the NAc lesions induced suboptimal choice behavior rather than simply promoting impulsive choice, suggesting that an intact NAc is necessary for optimal decision making.



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The application of graphene-based materials as chromatographic stationary phases

Publication date: Available online 15 November 2017
Source:TrAC Trends in Analytical Chemistry
Author(s): Xiaojing Liang, Xiudan Hou, James HM. Chan, Yong Guo, Emily F. Hilder
There is tremendous interest in graphene since its discovery. In the past few years, graphene-based materials attracted much attention in analytical chemistry due to their large surface area, π-electron-rich structure and good thermal and chemical stability. In this article, an overview of the most significant results so far achieved in the application of graphene-based materials: graphene, graphene oxide and graphene quantum dot as chromatographic stationary phases is presented. In particular, we focus on the separation performance in capillary gas chromatography, in high performance liquid chromatography and capillary electrochromatography. Different synthesis strategies (physical coating, chemical bonding and some other preparation techniques) in preparing graphene-based stationary phases and the relationship with chromatographic behavior is also considered. Finally, we discuss possible challenges and future perspectives in this rapidly developing field.



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Non-contributory social transfer programs in developing countries: A new dataset and research agenda

Publication date: February 2018
Source:Data in Brief, Volume 16
Author(s): Marina Dodlova, Anna Giolbas, Jann Lay
Social transfer programs in developing countries are designed to contribute to poverty reduction by increasing the income of the poor in order to ensure minimal living standards. In addition, social transfers provide a safety net for the vulnerable, who are typically not covered by contributory social security. The question of how effective such programs are in achieving these aims has been the subject of numerous impact evaluations. However, the optimal design of such programs is still unclear. Even less is known about whether the adoption and implementation of transfer programs is really driven by poverty and neediness or whether other factors also have an influence. To investigate these and other research questions, we have developed a new dataset entitled Non-Contributory Social Transfer Programs (NSTP) in Developing Countries. One advantage of this dataset is that it traces 186 non-contributory programs from 101 countries back in time and presents them in panel form for the period up until 2015. The second advantage is that it contains all the details regarding the various programs' designs as well as information on costs and coverage in a coded format and thus facilitates both comparative quantitative and in-depth qualitative analyses. While describing the data we discuss a number of examples of how the dataset can be used to explore different issues related to social policies in developing countries. We present suggestive evidence that the adoption of social transfer programs is not based only on pro-poor motives, but rather that social policy choices differ between political regimes.



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Home energy management (HEM) database: A list with coded attributes of 308 devices commercially available in the US

Publication date: February 2018
Source:Data in Brief, Volume 16
Author(s): Marco Pritoni, Rebecca Ford, Beth Karlin, Angela Sanguinetti
Policymakers worldwide are currently discussing whether to include home energy management (HEM) products in their portfolio of technologies to reduce carbon emissions and improve grid reliability. However, very little data is available about these products. Here we present the results of an extensive review including 308 HEM products available on the US market in 2015–2016. We gathered these data from publicly available sources such as vendor websites, online marketplaces and other vendor documents. A coding guide was developed iteratively during the data collection and utilized to classify the devices. Each product was coded based on 96 distinct attributes, grouped into 11 categories: Identifying information, Product components, Hardware, Communication, Software, Information - feedback, Information - feedforward, Control, Utility interaction, Additional benefits and Usability. The codes describe product features and functionalities, user interaction and interoperability with other devices. A mix of binary attributes and more descriptive codes allow to sort and group data without losing important qualitative information. The information is stored in a large spreadsheet included with this article, along with an explanatory coding guide. This dataset is analyzed and described in a research article entitled "Categories and functionality of smart home technology for energy management" (Ford et al., 2017) [1].



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Draft genome sequences of the oomycete Pythium insidiosum strain CBS 573.85 from a horse with pythiosis and strain CR02 from the environment

Publication date: February 2018
Source:Data in Brief, Volume 16
Author(s): Preecha Patumcharoenpol, Thidarat Rujirawat, Tassanee Lohnoo, Wanta Yingyong, Nongnuch Vanittanakom, Weerayuth Kittichotirat, Theerapong Krajaejun
Pythium insidiosum is an aquatic oomycete microorganism that causes the fatal infectious disease, pythiosis, in humans and animals. The organism has been successfully isolated from the environment worldwide. Diagnosis and treatment of pythiosis is difficult and challenging. Genome sequences of P. insidiosum, isolated from humans, are available and accessible in public databases. To further facilitate biology-, pathogenicity-, and evolution-related genomic and genetic studies of P. insidiosum, we report two additional draft genome sequences of the P. insidiosum strain CBS 573.85 (35.6Mb in size; accession number, BCFO00000000.1) isolated from a horse with pythiosis, and strain CR02 (37.7 Mb in size; accession number, BCFR00000000.1) isolated from the environment.



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