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Sub 5 nm

Nabih Lolak, Suleyman Akocak, Silvia Bua, Claudiu T Supuran
A series of novel ureido benzenesulfonamides incorporating 1,3,5-triazine moieties were obtained by reacting 4-isocyanato-benzenesulfonamide (2) with 2-amino-4,6-dicholoro-1,3,5-triazine (4). The 4-(3-(4,6-dichloro-1,3,5-triazin-2-yl)ureido) benzenesulfonamide (5) was subsequently derivatized by reaction with various nucleophiles such as, morpholine, ammonia, methyl amine, dimethyl amine, and piperidine. The ureido benzenesulfonamides incorporating triazinyl moieties were investigated as inhibitors of four selected physiologically relevant human carbonic anhydrase (hCA, EC 4...
October 5, 2018: Bioorganic Chemistry
Xiaoyang Yuan, Jing Wang, Hing Man Chan
Methylmercury (MeHg) is a ubiquitous environmental pollutant that is known to be neurotoxic, particularly during fetal development. However, the mechanisms responsible for MeHg-induced changes in adult neuronal function, when their exposure occurred primarily during fetal development, are not yet understood. We hypothesized that fetal MeHg exposure could affect neural precursor development leading to long-term neurotoxic effects. Primary cortical precursor cultures obtained from embryonic day 12 were exposed to 0 nM, 0...
October 10, 2018: Toxics
Kumud B Mishra, Anamika Mishra, Jiří Kubásek, Otmar Urban, Arnd G Heyer, Govindjee
Cold acclimation modifies the photosynthetic machinery and enables plants to survive at sub-zero temperatures, whereas in warm habitats, many species suffer even at non-freezing temperatures. We have measured chlorophyll a fluorescence (ChlF) and CO2 assimilation to investigate the effects of cold acclimation, and of low temperatures, on a cold-sensitive Arabidopsis thaliana accession C24. Upon excitation with low intensity (40 µmol photons m- 2 s- 1 ) ~ 620 nm light, slow (minute range) ChlF transients, at ~ 22 °C, showed two waves in the SMT phase (S, semi steady-state; M, maximum; T, terminal steady-state), whereas CO2 assimilation showed a linear increase with time...
October 10, 2018: Photosynthesis Research
Hongyu Zhao, Siyu Yao, Mengtao Zhang, Fei Huang, Qikui Fan, Shumeng Zhang, Hongyang Liu, Ding Ma, Chuanbo Gao
Ultra-small platinum nanoparticles loaded over titania is a promising catalyst for the low-temperature water-gas shift (WGS) reaction and shows the potential to work in a mobile hydrogen fuel cell system. Their precise size engineering (< 3 nm) and reliable stabilization remain challenging. To address these issues, we report a reverse-micelle synthesis approach, which affords uniform ultra-small platinum nanoparticles (tunable in ~1.0-2.6 nm) encapsulated in hollow titania nanospheres with a shell thickness of only ~3-5 nm and an overall diameter of only ~32 nm...
October 8, 2018: ACS Applied Materials & Interfaces
Preetam Hazra, K B Jinesh
Resistive Random Access Memory (ReRAM) has emerged as the successor to FLASH in memory technology due to its multi-level fabrication possibilities and prospects of scaling down virtually to atomic dimensions. However, as we report here, when polycrystalline switching materials are used, the ReRAM devices scaled down to the sub-5 nm2 area show complete randomness due to inhomogeneous conductance values of grains and grain boundaries. By measuring the switching properties of grains and grain boundaries individually using a scanning tunneling microscope, we demonstrate that the doublet and triplet grain boundaries behave like degenerate semiconductors and act as conduction channels that bypass the resistive switching of the devices...
October 5, 2018: Nanotechnology
Dhruba K Pattadar, Francis P Zamborini
Here we report on the very low size stability of electrocatalytically-active 1.5 to 2.0 nm diameter tetrakis(hydroxymethyl)phosphonium chloride-stabilized Au nanoparticles (THPC Au2nm NPs) chemically attached to glass/indium tin oxide electrodes. The potential for oxidative dissolution of THPC Au2nm NPs in the presence of bromide is about 250 mV negative of 4 nm diameter citrate-stabilized Au NPs (Cit Au4nm NPs) and 450 mV negative of bulk Au, which provides us with an easy method to assess the size stability using anodic stripping voltammetry (ASV)...
October 4, 2018: Journal of the American Chemical Society
Rhiannon M David, Nigel J Gooderham
Cooking food at high temperatures produces genotoxic chemicals and there is concern about their impact on human health. DNA damage caused by individual chemicals has been investigated but few studies have examined the consequences of exposure to mixtures as found in food. The current study examined the mutagenic response to binary mixtures of benzo[a]pyrene (BaP) with glycidamide (GA), BaP with acrylamide (AC), or 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) with GA at human-relevant concentrations (sub-nM)...
September 26, 2018: Archives of Toxicology
Chun-Ying Huang, Ming-Liang Chen, Chun-Wei Yu, Tsung-Chih Wan, Shih-Hsuan Chen, Chia-Yu Chang, Tzu-Yang Hsu
This study demonstrates dual functional hybrid heterojunction photodiodes (PDs) that comprise an amorphous indium gallium zinc oxide (a-IGZO) thin film blended with graphene nanoflakes and a SiO2 (5 nm)/Si substrate. The PDs exhibit a photo-responsivity of approximately 0.15-0.27 A W-1 under 633 nm illumination, which is much higher than that for a-IGZO based phototransistor in the visible region. The device also gives a long-lasting persistent photocurrent (PPC) when the UV light is extinguished. This results show that the hybrid heterojunction acts as a high performance photodetector for the detection of visible light and provides a universal scenario for development of PPC...
September 26, 2018: Nanotechnology
Chengyin Fu, M Belén Oviedo, Yihan Zhu, Arthur von Wald Cresce, Kang Xu, Guanghui Li, Mikhail E Itkis, Robert C Haddon, Miaofang Chi, Yu Han, Bryan M Wong, Juchen Guo
We demonstrate an unusual electrochemical reaction of sulfur with lithium upon encapsulation in narrow-diameter (subnanometer) single-walled carbon nanotubes (SWNTs). Our study provides mechanistic insight on the synergistic effects of sulfur confinement and Li+ ion solvation properties that culminate in a new mechanism of these sub-nanoscale-enabled reactions (which cannot be solely attributed to the lithiation-delithiation of conventional sulfur). Two types of SWNTs with distinct diameters, produced by electric arc (EA-SWNTs, average diameter 1...
September 27, 2018: ACS Nano
François Noël, Pedro Azalim, Fernando M do Monte, Luis Eduardo M Quintas, Adriana Katz, Steven J D Karlish
INTRODUCTION: Ouabain and digoxin are classical inhibitors of the Na+ ,K+ -ATPase. In addition to their conventional uses as therapeutic agents or experimental tools there is renewed interest due to evidence suggesting they could be endogenous hormones. Somewhat surprisingly, different publications show large discrepancies in potency for inhibiting Na+ ,K+ -ATPase activity (IC50 ), particularly for the slow binding inhibitors, ouabain and digoxin. METHODS: Using purified pig kidney Na+ ,K+ -ATPase (α1β1FXYD2) and purified detergent-soluble recombinant human Na+ ,K+ -ATPase (α1β1FXYD1) we have re-evaluated binding and inhibition kinetics and effects of K+ concentration for ouabain, digoxin, ouabagenin and digoxigenin...
September 20, 2018: Journal of Pharmacological and Toxicological Methods
Jackie L Whittaker, Clodagh M Toomey, Alberto Nettel-Aguirre, Jacob L Jaremko, Patricia K Doyle-Baker, Linda J Woodhouse, Carolyn A Emery
PURPOSE: Active youth are vulnerable to knee injury and subsequent osteoarthritis. Improved understanding of the association between health-related outcomes and history of joint injury could inform osteoarthritis prevention strategies. The purpose of this historical cohort study is to examine the association between youth sport-related knee injury and various clinical, physiological, behavioral and functional health-related outcomes, 3-10 years post-injury. METHODS: Participants included 100 individuals who experienced a youth sport-related knee injury 3-10 years earlier and 100 age, sex and sport-matched uninjured controls...
September 19, 2018: Medicine and Science in Sports and Exercise
Margret Schottelius, Alexander Wurzer, Katharina Wissmiller, Roswitha Beck, Maximilian Koch, Dimitrios Gkorpas, Johannes Notni, Tessa Buckle, Matthias N van Oosterom, Katja Steiger, Vasilis Ntziachristos, Markus Schwaiger, Fijs W B van Leeuwen, Hans-Jürgen Wester
The PSMA-targeted radiotracers 68 Ga/177 Lu-PSMA-I&T and 99m Tc-PSMA-I&S are currently successfully employed for clinical PET imaging, radionuclide therapy and radioguided surgery of metastatic prostate cancer. To additionally exploit the high sensitivity and spatial resolution of fluorescence imaging for improved surgical guidance, a first PSMA-I&T-based hybrid tracer, PSMA-I&F (DOTAGA-k(Sulfo-Cy5)-y-nal-k-Sub-KuE), has been developed and evaluated. The in vitro PSMA-targeting efficiency of PSMA-I&F, the reference PSMA-I&T and their corresponding natGa-/68 Ga- and natLu/177 Lu-counterparts was determined in LNCaP cells via competitive binding assays (IC50), dual-tracer radioligand- and fluorescence internalization studies...
September 20, 2018: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
Xuejiao Wang, Xupeng Zhu, Huimin Shi, Yiqin Chen, Zhiquan Chen, Yixuan Zeng, Zhixiang Tang, Huigao Duan
Seeking for ultrasensitive and low-cost substrates is highly demandable for practical applications of surface-enhanced Raman scattering (SERS) technology. In this work, we report an ultrasensitive SERS-active substrate based on wet-chemistry-synthesized vertically aligned large-area TiO2 nanosheets (NSs) decorated by densely packed gold nanoparticles (Au NPs) with sub-5 nm gaps. Via a multistep successive deposition process, three-dimensional-stacked Au NPs sandwiched by a 3 nm SiO2 layer were assembled onto the TiO2 NS, enabling numerous hotspots due to the formation of both ultratiny plasmonic gaps and semiconductor/metal interfaces...
October 4, 2018: ACS Applied Materials & Interfaces
Min Ju Kim, Kwanyong Pak, Wan Sik Hwang, Sung Gap Im, Byung Jin Cho
Organic-inorganic hybrid dielectrics have attracted considerable attention for improving both the dielectric constant ( k) and mechanical flexibility of the gate dielectric layer for emerging flexible and wearable electronics. However, conventional solution-based hybrid materials, such as nanocomposite and self-assembled nanodielectrics, have limitations in the dielectric quality when the thickness is deep-scaled, which is critical to realizing high-performance flexible devices. This study proposes a novel vapor-phase synthesis method to form an ultrathin, homogeneous, high- k organic-inorganic hybrid dielectric...
September 28, 2018: ACS Applied Materials & Interfaces
François Lux, Vu Long Tran, Eloïse Thomas, Sandrine Dufort, Fabien Rossetti, Matteo Martini, Charles Truillet, Tristan Doussineau, Guillaume Bort, Franck Denat, Frédéric Boschetti, Goran Angelovski, Alexandre Detappe, Yannick Crémillieux, Nathalie Mignet, Bich-Thuy Doan, Benoit Larrat, Sébastien Meriaux, Emmanuel Barbier, Stéphane Roux, Peter Fries, Andreas Müller, Marie-Caline Abadjian, Carolyn Anderson, Emmanuelle Canet-Soulas, Penelope Bouziotis, Muriel Barberi-Heyob, Céline Frochot, Camille Verry, Jacques Balosso, Michael Evans, Jacqueline Sidi-Boumedine, Marc Janier, Karl Butterworth, Stephen McMahon, Kevin Prise, Marie-Thérèse Aloy, Dominique Ardail, Claire Rodriguez-Lafrasse, Erika Porcel, Sandrine Lacombe, Ross Berbeco, Awatef Allouch, Jean-Luc Perfettini, Cyrus Chargari, Eric Deutsch, Géraldine Le Duc, Olivier Tillement
AGuIX® are sub-5 nm nanoparticles made of a polysiloxane matrix and gadolinium chelates. This nanoparticle has been recently accepted in clinical trials in association with radiotherapy. This review will summarize the principal preclinical results that have led to first in man administration. No evidence of toxicity has been observed during regulatory toxicity tests on two animal species (rodents and monkeys). Biodistributions on different animal models have shown passive uptake in tumours due to enhanced permeability and retention effect combined with renal elimination of the nanoparticles after intravenous administration...
September 18, 2018: British Journal of Radiology
Xiao Lin, Rajeev K Naidu, Jinhui Dai, Xingtao Zhou, Xiaomei Qu, Hao Zhou
Background This study aims to assess the efficacy of the scleral collagen cross-linking method using glyceraldehyde solution for prevention of lens-induced axial elongation in New Zealand rabbits, and investigate the biochemical and microstructural changes that occur. Methods The right eyes of New Zealand rabbits aged seven weeks were randomly divided into three groups: the cross-linking group (n = 6), non-crosslinking group (n = 5), and untreated control group (n = 5). Eyes in cross-linking and non-crosslinking groups were treated with a -8...
September 17, 2018: Current Eye Research
Ting Cheng, Riccardo Marin, Artiom Skripka, Fiorenzo Vetrone
In the context of light-mediated tumor treatment, the application of ultraviolet (UV) radiation can initiate drug release and photodynamic therapy. However, its limited penetration depth in tissues impedes the subcutaneous applicability of such radiation. On the contrary, near-infrared (NIR) light is not energetic enough to initiate secondary photochemical processes, but can pierce tissues at a significantly greater depth. Upconverting nanoparticles (UCNPs) unify the advantages of both extremes of the optical spectrum, they can be excited by NIR irradiation and emit UV light through the process of upconversion, effective NIR-to-UV generation being attained with UCNPs as large as 100 nm...
September 28, 2018: Journal of the American Chemical Society
A F Kornev, R V Balmashnov, I G Kuchma, A S Davtian, D O Oborotov
We demonstrate a diode-pumped master oscillator power amplifier Nd:YAG 1064 nm laser with sub-joule-level output energy of 0.43 J, high pulse repetition rate of 200 Hz, and short pulse duration of 100 ps. The 5 mJ master oscillator consisted of a 100 nJ/100 ps Nd:YVO4 microchip laser and end-pumped Nd:YAG regenerative amplifier. The two-pass output amplifier was based on two ∅10×140  mm Nd:YAG laser rods. We apply an adaptive compensator with an analyzer based on an astigmatic optical system and a quadrant photodiode to compensate for low-order wave-front non-stationary thermal distortions in a high-energy laser amplifier...
September 15, 2018: Optics Letters
Mini Agarwal, Asokan Kandasami, Sandeep Kumar Garg, Ekta Dhamija, Pratik Kumar
The present paper reports the structural, morphological and optical properties of nanophosphor Li3B7O12:Mn with the optimized dopant concentration 0.25 mol% and its surface modification under the irradiations of 250 keV proton beams and gamma photons for ion fluence ranging from 1 × 1013 to 6.25 × 1015 ions cm-2 and doses from 100mGy to 100Gy, respectively. This nanophosphor has been synthesised by high temperature solid state reaction method. Its optical properties are characterized by Optically Stimulated Luminescence (OSL) and Thermo luminescence (TL) techniques...
September 10, 2018: Journal of Radiological Protection: Official Journal of the Society for Radiological Protection
Sa Weon Hong, A Jonathan Singh, Vimal Patel, Euan R Russell, Jessica J Field, John H Miller, Peter T Northcote
A new peloruside congener, peloruside E (5), has been isolated in sub-milligram quantities from a specimen of the New Zealand marine sponge Mycale hentscheli. The structure of 5 differs from the parent compound peloruside A (1) by replacement of the C-10 gem-dimethyl moiety with a monomethyl substituent and represents the first structural deviation in the pelorusane scaffold. Peloruside E (5) is potently antiproliferative (HL-60, IC50 90 nM, cf. 1, 19 nM) and polymerizes purified tubulin, albeit at a rate lower than that of 1...
September 28, 2018: Journal of Natural Products
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