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https://www.readbyqxmd.com/read/28647127/infrared-light-detection-by-the-haller-s-organ-of-adult-american-dog-ticks-dermacentor-variabilis-ixodida-ixodidae
#1
Robert D Mitchell, Jiwei Zhu, Ann L Carr, Anirudh Dhammi, Grayson Cave, Daniel E Sonenshine, R Michael Roe
The Haller's organ (HO), unique to ticks and mites, is found only on the first tarsus of the front pair of legs. The organ has an unusual morphology consisting of an anterior pit (AP) with protruding sensilla and a posterior capsule (Cp). The current thinking is that the HO's main function is chemosensation analogous to the insect antennae, but the functionality of its atypical structure (exclusive to the Acari) is unexplained. We provide the first evidence that the HO allows the American dog tick, Dermacentor variabilis, to respond to infrared (IR) light...
June 13, 2017: Ticks and Tick-borne Diseases
https://www.readbyqxmd.com/read/28646176/enhanced-atomic-desorption-of-209-and-210-francium-from-organic-coating
#2
Steinn Agustsson, Giovanni Bianchi, Roberto Calabrese, Lorenzo Corradi, Antonio Dainelli, Alen Khanbekyan, Carmela Marinelli, Emilio Mariotti, Luca Marmugi, Leonardo Ricci, Leonardo Stiaccini, Luca Tomassetti, Andrea Vanella
Controlled atomic desorption from organic Poly-DiMethylSiloxane coating is demonstrated for improving the loading efficiency of (209,210)Fr magneto-optical traps. A three times increase in the cold atoms population is obtained with contact-less pulsed light-induced desorption, applied to different isotopes, either bosonic or fermionic, of Francium. A six times increase of (210)Fr population is obtained with a desorption mechanism based on direct charge transfer from a triboelectric probe to the adatom-organic coating complex...
June 23, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28646167/effectively-infinite-optical-path-length-created-using-a-simple-cubic-photonic-crystal-for-extreme-light-trapping
#3
Brian J Frey, Ping Kuang, Mei-Li Hsieh, Jian-Hua Jiang, Sajeev John, Shawn-Yu Lin
A 900 nm thick TiO2 simple cubic photonic crystal with lattice constant 450 nm was fabricated and used to experimentally validate a newly-discovered mechanism for extreme light-bending. Absorption enhancement was observed extending 1-2 orders of magnitude over that of a reference TiO2 film. Several enhancement peaks in the region from 600-950 nm were identified, which far exceed both the ergodic fundamental limit and the limit based on surface-gratings, with some peaks exceeding 100 times enhancement...
June 23, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28644638/ferroelectric-domain-patterning-controlled-schottky-junction-state-in-monolayer-mos_-2
#4
Zhiyong Xiao, Jingfeng Song, David K Ferry, Stephen Ducharme, Xia Hong
We exploit scanning-probe-controlled domain patterning in a ferroelectric top layer to induce nonvolatile modulation of the conduction characteristic of monolayer MoS_{2} between a transistor and a junction state. In the presence of a domain wall, MoS_{2} exhibits rectified I-V characteristics that are well described by the thermionic emission model. The induced Schottky barrier height Φ_{B}^{eff} varies from 0.38 to 0.57 eV and is tunable by a SiO_{2} global back gate, while the tuning range of Φ_{B}^{eff} depends sensitively on the conduction-band-tail trapping states...
June 9, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28643701/self-anti-reflective-density-modulated-thin-films-by-hips-technique
#5
Filiz Keles, Emad O Badraddin, Tansel Karabacak
A critical factor for an efficient light harvesting device is reduced reflectance in order to achieve high optical absorptance. In this regard, refractive index engineering becomes important to minimize reflectance. In this study, a new fabrication approach to obtain the density-modulated CuInxGa(1-x)Se2 (CIGS) thin films with self-anti-reflective properties has been demonstrated. Density-modulated CIGS samples were fabricated by utilizing high pressure sputtering (HIPS) at Ar gas pressure of 2.75 x 10-2 mbar along with the conventional low pressure sputtering (LPS) at Ar gas pressure of 3...
June 23, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28642346/detergent-induced-self-assembly-and-controllable-photosensitizer-activity-of-diester-phenylene-ethynylenes
#6
Patrick L Donabedian, Matthew N Creyer, Florencia A Monge, Kirk S Schanze, Eva Y Chi, David G Whitten
Photodynamic therapy, in which malignant tissue is killed by targeted light exposure following administration of a photosensitizer, can be a valuable treatment modality but currently relies on passive transport and local irradiation to avoid off-target oxidation. We present a system of excited-state control for truly local delivery of singlet oxygen. An anionic phenylene ethynylene oligomer is initially quenched by water, producing minimal fluorescence and no measurable singlet oxygen generation. When presented with a binding partner, in this case an oppositely charged surfactant, changes in solvent microenvironment result in fluorescence unquenching, restoration of intersystem crossing to the triplet state, and singlet oxygen generation, as assayed by transient absorption spectroscopy and chemical trapping...
June 22, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28640628/oriented-gold-nanorods-and-gold-nanorod-chains-within-smectic-liquid-crystal-topological-defects
#7
Brigita Rožič, Jérôme Fresnais, Celine Molinaro, Joseph Calixte, Shivakumar Umadevi, Stephanie Lau-Truong, Nordin Felidj, Tobias Kraus, Fabrice Charra, Vincent Dupuis, Torsten Hegmann, Celine Fiorini-Debuisschert, Bruno Gallas, Emmanuelle Lacaze
We show that the use of oriented linear arrays of smectic A defects, the so-called smectic oily streaks, enables the orientation of gold nanorods (GNRs) for a large range of GNR diameters, ranging from 7 to 48 nm, and for various ligands. For the small GNRs it enables oriented end-to-end small chains of GNRs when the density is increased from around 2 GNRs/μm(2) to around 6 GNRs/μm(2). We have characterized the orientation of single GNRs by spectrophotometry and two-photon luminescence (TPL). A strongly anisotropic absorption of the composites and an on-off switching of GNR luminescence, both controlled by incident light polarization, are observed, revealing an orientation of the GNRs mostly parallel to the oily streaks...
June 22, 2017: ACS Nano
https://www.readbyqxmd.com/read/28640626/photocatalytic-hydrazonyl-radical-mediated-radical-cyclization-allylation-cascade-synthesis-of-dihydropyrazoles-and-tetrahydropyridazines
#8
Quan-Qing Zhao, Jun Chen, Dong-Mei Yan, Jia-Rong Chen, Wen-Jing Xiao
A novel photocatalytic hydrazonyl radical-mediated radical cyclization/allylation cascade reaction of β,γ-unsaturated hydrazones is developed using allyl sulfones and Morita-Baylis-Hillman adduct as allyl sources, which provides an efficient and practical access to various diversely functionalized dihydropyrazoles and tetrahydropyridazines. The reaction is enabled by controllable generation of hydrazonyl radicals via an oxidative deprotonation electron transfer strategy and selective trapping of the resultant C-centered radicals under visible light irradiation...
June 22, 2017: Organic Letters
https://www.readbyqxmd.com/read/28638067/highly-efficient-photocatalytic-degradation-of-methylene-blue-by-popd-modified-tio-2-nanocomposites-due-to-photosensitization-synergetic-effect-of-tio2-with-popd
#9
Chuanxi Yang, Wenping Dong, Guanwei Cui, Yingqiang Zhao, Xifeng Shi, Xinyuan Xia, Bo Tang, Weiliang Wang
Poly-o-phenylenediamine modified TiO2 nanocomposites were successfully synthesized via an 'in situ' oxidative polymerization method. The modified nanocomposites were characterized by BET, XRD, TEM, FT-IR, TGA, XPS, EA and UV-Vis DRS. The photocatalytic degradation of methylene blue was chosen as a model reaction to evaluate the photocatalytic activities of TiO2 and PoPD/TiO2. The results indicated that PoPD/TiO2 nanocomposites exhibited good photocatalytic activity and stability. The photocatalytic activity of PoPD/TiO2 increased as the initial pH increased because of electrostatic adsorption between the photocatalyst and MB as well as the generation of ·OH, whereas it exhibited an earlier increasing and later decreasing trend as the concentration of the photocatalyst increased owing to the absorption of visible light...
June 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28637467/imported-plasmodium-falciparum-and-locally-transmitted-plasmodium-vivax-cross-border-malaria-transmission-scenario-in-northwestern-thailand
#10
Patchara Sriwichai, Stephan Karl, Yudthana Samung, Kirakorn Kiattibutr, Jeeraphat Sirichaisinthop, Ivo Mueller, Liwang Cui, Jetsumon Sattabongkot
BACKGROUND: Cross-border malaria transmission is an important problem for national malaria control programmes. The epidemiology of cross-border malaria is further complicated in areas where Plasmodium falciparum and Plasmodium vivax are both endemic. By combining passive case detection data with entomological data, a transmission scenario on the northwestern Thai-Myanmar border where P. falciparum is likely driven by importation was described, whereas P. vivax is also locally transmitted...
June 21, 2017: Malaria Journal
https://www.readbyqxmd.com/read/28636398/ultrafast-carrier-trapping-in-thick-shell-colloidal-quantum-dots
#11
Ankit Jain, Oleksandr Voznyy, Marek Korkusinski, Pawel Hawrylak, Edward H Sargent
It has previously been found that Auger processes can lead to femtosec- ond carrier trapping in quantum dots, limiting their performance in opto- electronic applications that rely on radiative recombination. Here, using atomistic simulations, we investigate whether a shell can protect carriers from Auger-assisted trapping. For these studies we investigate CdSe/CdS core-shell quantum dots having total diameters reaching up to 10 nm. We find trapping lifetimes as fast as 1 ps for 2 nm shells, and we report that shells as thick as 6 nm are required to suppress trapping fully...
June 21, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28636313/iodine-iii-reagents-in-radical-chemistry
#12
Xi Wang, Armido Studer
The chemistry of hypervalent iodine(III) compounds has gained great interest over the past 30 years. Hypervalent iodine(III) compounds show valuable ionic reactivity due to their high electrophilicity but also express radical reactivity as single electron oxidants for carbon and heteroatom radical generation. Looking at ionic chemistry, these iodine(III) reagents can act as electrophiles to efficiently construct C-CF3, X-CF3 (X = heteroatom), C-Rf (Rf = perfluoroalkyl), X-Rf, C-N3, C-CN, S-CN, and C-X bonds...
June 21, 2017: Accounts of Chemical Research
https://www.readbyqxmd.com/read/28635254/sudoku-like-lab-on-paper-cyto-device-with-dual-enhancement-of-electrochemiluminescence-intermediates-strategy
#13
Hongmei Yang, Yan Zhang, Li Li, Lina Zhang, Feifei Lan, Jinghua Yu
This paper describes the design and construction of sudoku-like lab-on-paper platform, in which dual enhancement of reaction intermediates strategy was incorporated for multiplexed competitive electrochemiluminescence (ECL) cyto-assay. Benefit from the sudoku-like structure, integrated multifunction were obtained on such elaborately devised platform, including specific reagents storage, multiple samples immobilization, residual automatic washing, and signal collection. By utilizing semicarbazide (SE) and silver nanoparticles (AgNPs) as dual enhancers, more ECL intermediates could be obtained in the graphene quantum dots (GQDs) and peroxydisulfate system, resulting in the production of more excited state GQDs to emit light...
June 21, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28634845/histomorphometric-and-immunohistochemical-evaluation-of-collagen-containing-xenogeneic-bone-blocks-used-for-lateral-bone-augmentation-in-staged-implant-placement
#14
Alberto Ortiz-Vigón, Sergio Martinez-Villa, Iñaki Suarez, Fabio Vignoletti, Mariano Sanz
BACKGROUND: The osteoconductive properties of collagen containing xenogeneic bone blocks (CCXBB) remain unclear. The aim of this prospective single-arm clinical study was to assess the histological outcomes of CCXBB blocks used as bone replacement grafts for lateral bone augmentation procedures. METHODS: In 15 patients with severe horizontal alveolar ridge resorption, lateral augmentation procedures were performed using CCXBB as bone replacement grafts. Twenty-six weeks postoperatively, a re-entry procedure was performed to evaluate the bone width for adequate implant placement and two histological specimens were retrieved from each patient, one being processed for ground sectioning and the other for decalcified paraffin-included sections...
December 2017: International Journal of Implant Dentistry
https://www.readbyqxmd.com/read/28630442/ir-sensitivity-enhancement-of-cmos-image-sensor-with-diffractive-light-trapping-pixels
#15
Sozo Yokogawa, Itaru Oshiyama, Harumi Ikeda, Yoshiki Ebiko, Tomoyuki Hirano, Suguru Saito, Takashi Oinoue, Yoshiya Hagimoto, Hayato Iwamoto
We report on the IR sensitivity enhancement of back-illuminated CMOS Image Sensor (BI-CIS) with 2-dimensional diffractive inverted pyramid array structure (IPA) on crystalline silicon (c-Si) and deep trench isolation (DTI). FDTD simulations of semi-infinite thick c-Si having 2D IPAs on its surface whose pitches over 400 nm shows more than 30% improvement of light absorption at λ = 850 nm and the maximum enhancement of 43% with the 540 nm pitch at the wavelength is confirmed. A prototype BI-CIS sample with pixel size of 1...
June 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28628208/carbocyclic-c-c-bond-formation-intramolecular-radical-ring-closure-to-yield-diastereomerically-pure-7-s-me-or-7-r-me-carba-lna-nucleotide-analogs
#16
Oleksandr Plashkevych, Ram Shankar Upadhayaya, Jyoti Chattopadhyaya
In light of the impressive gene-silencing properties of carba-LNA modified oligo DNA and RNA, both in antisense RNA and siRNA approaches, which have been confirmed as proof-of-concept for biochemical applications in post-transcriptional gene silencing, we envision the true potential of carba-LNA modifications to be revealed soon. Herein we provide detailed protocols for synthesis of carba-LNA-A, -G, -(5-Me) C, and -T nucleosides on a medium/large scale (gram scale), as well as important guidelines for incorporation of these modified carba-LNAs into DNA or RNA oligonucleotides...
June 19, 2017: Current Protocols in Nucleic Acid Chemistry
https://www.readbyqxmd.com/read/28627563/highly-efficient-visible-light-driven-photocatalytic-degradation-of-tetracycline-by-a-z-scheme-g-c3n4-bi3tao7-nanocomposite-photocatalyst
#17
Bifu Luo, Min Chen, Zhengyuan Zhang, Jie Xu, Di Li, Dongbo Xu, Weidong Shi
Spatial separation of photogenerated electron-hole pairs is one of the most important factors that determine the efficiency of a photocatalyst. It is well acknowledged that the fabrication of heterogeneous photocatalysts with two different inorganic semiconductors is a good strategy to effectively improve the charge separation of electrons and holes. This study describes a novel visible light-induced g-C3N4/Bi3TaO7 composite photocatalyst with superior photocatalytic properties toward the degradation of tetracycline (TC) by visible light irradiation...
June 19, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28623322/design-of-non-deterministic-quasi-random-nanophotonic-structures-using-fourier-space-representations
#18
Shuangcheng Yu, Chen Wang, Yichi Zhang, Biqin Dong, Zhen Jiang, Xiangfan Chen, Wei Chen, Cheng Sun
Despite their seemingly random appearances in the real space, quasi-random nanophotonic structures exhibit distinct structural correlations and have been widely utilized for effective photon management. However, current design approaches mainly rely on the deterministic representations consisting two-dimensional (2D) discretized patterns in the real space. They fail to capture the inherent non-deterministic characteristic of the quasi-random structures and inevitably result in a large design dimensionality...
June 16, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28621997/cooling-a-harmonic-oscillator-by-optomechanical-modification-of-its-bath
#19
Xunnong Xu, Thomas Purdy, Jacob M Taylor
Optomechanical systems show tremendous promise for the high-sensitivity sensing of forces and modification of mechanical properties via light. For example, similar to neutral atoms and trapped ions, laser cooling of mechanical motion by radiation pressure can take single mechanical modes to their ground state. Conventional optomechanical cooling is able to introduce an additional damping channel to mechanical motion while keeping its thermal noise at the same level, and, as a consequence, the effective temperature of the mechanical mode is lowered...
June 2, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28618583/phase-transitions-at-high-energy-vindicate-negative-microcanonical-temperature
#20
P Buonsante, R Franzosi, A Smerzi
The notion of negative absolute temperature emerges naturally from Boltzmann's definition of "surface" microcanonical entropy in isolated systems with a bounded energy density. Recently, the well-posedness of such construct has been challenged, on account that only the Gibbs "volume" entropy-and the strictly positive temperature thereof-would give rise to a consistent thermodynamics. Here we present analytical and numerical evidence that Boltzmann microcanonical entropy provides a consistent thermometry for both signs of the temperature...
May 2017: Physical Review. E
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