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Ryotaro Bouchi, Tatsuya Fukuda, Takato Takeuchi, Yujiro Nakano, Masanori Murakami, Isao Minami, Hajime Izumiyama, Koshi Hashimoto, Takanobu Yoshimoto, Yoshihiro Ogawa
BACKGROUND: Activation of dipeptidyl peptidase 4 (DPP4) has been reported to be associated with impairment of insulin signaling in skeletal muscle mass, presumably leading to loss of muscle function. This study was aimed to investigate whether the use of DPP4 inhibitors (DPP4i) could attenuate the progressive loss of muscle mass in patients with type 2 diabetes. METHODS: A total 105 patients with type 2 diabetes (mean age 62 ± 12 years; 39% female) were studied in this retrospective observational study...
October 20, 2017: Diabetes/metabolism Research and Reviews
Sung-Il Baik, Dieter Isheim, David N Seidman
Atom-probe tomography (APT) is a unique analysis tool that enables true three-dimensional (3-D) analyses with sub-nano scale spatial resolution. Recent implementations of the local-electrode atom-probe (LEAP) tomograph with ultraviolet laser pulsing have significantly expanded the research applications of APT. The small field-of-view of a needle-shaped specimen with a less than 100 nm diam. is, however, a major limitation for analyzing materials. The systematic approaches for site-specific targeting of an APT nanotip in a transmission electron microscope (TEM) of a thin sample are introduced to solve the geometrical limitations of a sharpened APT nanotip...
October 12, 2017: Ultramicroscopy
Chenhu Zhang, Sun Wei, Yuehua Hu, Honghu Tang, Jiande Gao, Zhigang Yin, Qingjun Guan
Selective adsorption of tannic acid (TA) on calcite surfaces and the implications of this process for the separation of fluorite ore were studied by microflotation tests, surface adsorption experiments, zeta potential measurements, UV-vis analysis, and X-ray photoelectron spectroscopy (XPS) analysis. The microflotation tests indicated that TA, when added before sodium oleate (NaOl), could selectively depress calcite from fluorite at pH 7. Surface adsorption experiments revealed that TA hinders the interaction of NaOl with calcite...
October 12, 2017: Journal of Colloid and Interface Science
Yuesheng Gao, Zhiyong Gao, Wei Sun, Zhigang Yin, Jianjun Wang, Yuehua Hu
The efficient separation of scheelite from calcium-bearing minerals, especially calcite, remains a challenge in practice. In this work, a novel reagent scheme incorporating a depressant of sodium hexametaphosphate (SHMP) and a collector mixture of octyl hydroxamic acid (HXMA-8) and sodium oleate (NaOl) was employed in both single and mixed binary mineral flotation, and it proved to be highly effective for the separation. Furthermore, the role of the pH value in the separation was evaluated. Additionally, the mechanism of the selective separation was investigated systemically via zeta potential measurements, fourier transform infrared (FTIR) spectroscopy analysis, X-ray photoelectron (XPS) spectroscopy analysis and crystal chemistry calculations...
October 12, 2017: Journal of Colloid and Interface Science
Supanan Anuchai, Sukon Phanichphant, Doldet Tantraviwat, Prayoonsak Pluengphon, Thiti Bovornratanaraks, Burapat Inceesungvorn
The introduction of oxygen vacancies (Vos) into tin dioxide crystal structure has been found as an effective method to improve its photocatalytic performance. Herein, oxygen-deficient tin dioxide (SnO2-x) nanocrystals were successfully prepared via a facile, one-step hydrothermal method at the temperature lower than those reported previously. The effect of hydrothermal temperature on phase composition and Vos content was also firstly investigated. Due to its high oxygen vacancy concentration, the SnO2-x prepared at 80 °C provides the best photocatalytic degradation of methyl orange under UV-visible light...
October 13, 2017: Journal of Colloid and Interface Science
Scott Ayton, Simon A James, Ashley I Bush
In this issue of Cell Chemical Biology, Telling et al. (2017) apply advanced X-ray microscopy techniques to reveal magnetite iron species in plaques from a mouse model of Alzheimer's disease. The characterization of abnormal iron chemistry in the disease model highlights the potential for iron to combine with the β-amyloid peptide and accelerate the disease process.
October 19, 2017: Cell Chemical Biology
Yunzhong Chen, Robert J Green, Ronny Sutarto, Feizhou He, Søren Linderoth, George Sawatzky, Nini Pryds
Polar discontinuities and redox reactions provide alternative paths to create two-dimensional electron liquids (2DELs) at oxide interfaces. Herein, we report high mobility 2DELs at interfaces involving SrTiO3 (STO) achieved using polar La7/8Sr1/8MnO3 (LSMO) buffer layers to manipulate both polarities and redox reactions from disordered overlayers grown at room temperature. Using resonant x-ray reflectometry experiments, we quantify redox reactions from oxide overlayers on STO as well as polarity induced electronic reconstruction at epitaxial LSMO/STO interfaces...
October 20, 2017: Nano Letters
Haruki Nagashima, Kumiko Shiraishi, Saori Ohkawa, Yuki Sakamoto, Kenshi Komatsu, Shinya Matsuura, Akira Tachibana, Hiroshi Tauchi
It is difficult to distinguish radiation-induced events from spontaneous events during induction of stochastic effects, especially in the case of low-dose or low-dose-rate exposures. By using a hypersensitive system for detecting somatic mutations at the HPRT1 locus, we investigated the frequency and spectrum of mutations induced by low-dose X-rays. The mutant frequencies induced by doses of >0.15 Gy were statistically significant when compared with the spontaneous frequency, and a clear dose dependency was also observed for mutant frequencies at doses of >0...
October 19, 2017: Journal of Radiation Research
Benjamin C Jewkes, Linda A Barlow, Eugene R Delay
Radiotherapy is one of the most common treatments for head and neck cancers, with an almost obligate side effect of altered taste (Conger 1973). In mice, targeted irradiation of the head and neck causes transient repression of proliferation of basal epithelial cells responsible for taste cell replacement, leading to a temporary depletion of taste sensory cells within taste buds, including Type II taste cells involved in detection of sweet stimuli (Nguyen et al. 2012). These findings suggest that irradiation may elevate sucrose detection thresholds, peaking at 7 days post-irradiation when loss of Type II cells is greatest...
October 19, 2017: Chemical Senses
Edis Dzananovic, Astha, Grzegorz Chojnowski, Soumya Deo, Evan P Booy, Pauline Padilla-Meier, Kevin McEleney, Janusz M Bujnicki, Trushar R Patel, Sean A McKenna
Highly structured RNA derived from viral genomes is a key cellular indicator of viral infection. In response, cells produce the interferon inducible RNA-dependent protein kinase (PKR) that, when bound to viral dsRNA, phosphorylates eukaryotic initiation factor 2α and attenuates viral protein translation. Adenovirus can evade this line of defence through transcription of a non-coding RNA, VAI, an inhibitor of PKR. VAI consists of three base-paired regions that meet at a three-way junction; an apical stem responsible for the interaction with PKR, a central stem required for inhibition, and a terminal stem...
2017: PloS One
Jing Wang, Junhong Guo, Jing Chen
We fabricated a silicon nanocrystal (NC) suspension with visible, continuous, tunable light emission with pH sensitivity from violet to blue-green. Transmission electron microscopy (TEM) images and X-ray diffraction (XRD) pattern analysis exhibit the highly crystalline nanoparticles of silicon. Photoluminescence (PL) spectra and photoluminescence excitation (PLE) spectra at different pH values, such as 1, 3, 5, 7, 9, and 11, reveal the origins of light emission from the silicon NC suspension, which includes both the quantum confinement effect and surface bonding...
October 20, 2017: Sensors
Wei Li, Juyan Liu, Chao Ding, Gang Bai, Jie Xu, Qingying Ren, Jinze Li
Ordered SnO₂ nanostructures were prepared as humidity sensors by nanosphere lithography with the magnetron sputtering technique. The X-ray diffraction patterns of SnO₂ nanostructures show that all intense diffraction peaks correspond to the crystallographic planes of SnO₂. The Atomic Force Microscope (AFM) mage shows that these SnO₂ nanostructures exhibited a classic honeycomb structure. The resistance of this sensor was measured to show that the resistance of the sensor decreases with an increase from lower relative humidity (RH) to higher RH...
October 20, 2017: Sensors
Gigliola Lusvardi, Corrado Barani, Federica Giubertoni, Giulia Paganelli
The aim of this manuscript was the optimization of the synthesis of TiO₂ nanoparticles (TiO₂ NPs) with conditions that could be easily reproducible at the industrial level. Several procedures were tested and those with C12H28O₄Ti and CO(NH₂)₂ as precursors seemed the most promising and, consequently, were improved with different molar ratios, lower temperatures and the addition of NH₄Cl as a secondary dopant of nitrogen. The obtained samples were studied with analytical techniques such as X-ray powder diffraction (XRPD) and field emission scanning electron microscopy (FESEM)...
October 20, 2017: Materials
Juncai Dong, Hurong Yao, Zhiying Guo, Quanjie Jia, Yan Wang, Pengfei An, Yu Gong, Yaxiang Liang, Dongliang Chen
Despite the great importance in fundamental and industrial fields, understanding structural changes for pressure-induced polyamorphism in network-forming glasses remains a formidable challenge. Here, we revisited the local structural transformations in GeO2 glass up to 54 GPa using x-ray absorption fine structure (XAFS) spectroscopy via a combination diamond anvil cell and polycapillary half-lens. Three polyamorphic transitions can be clearly identified by XAFS structure refinement. First, a progressive increase of the nearest Ge-O distance and bond disorder to a maximum at ~5-16 GPa, in the same pressure region of previously observed tetrahedral-octahedral transformation...
October 20, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
Sofia D'Abrantes, Sarah Gratton, Pamela Reynolds, Verena Kriechbaumer, Joseph McKenna, Stephen Barnard, Dave Clarke, Stanley W Botchway
Genomic deoxyribonucleic acid (DNA) is continuously being damaged by endogenous processes such as metabolism or by exogenous events such as radiation. The specific phosphorylation of histone H2AX on serine residue 139, described as γ-H2AX, is an excellent indicator or marker of DNA double-strand breaks (DSBs). The yield of γ-H2AX (foci) is shown to have some correlation with the dose of radiation or other DSB-causing agents. However, there is some discrepancy in the DNA DSB foci yield among imaging and other methods such as gel electrophoresis...
October 20, 2017: Radiation Research
Alexander S Riegert, James B Thoden, Ian C Schoenhofen, David C Watson, N Martin Young, Peter A Tipton, Hazel M Holden
Within recent years it has become apparent that protein glycosylation is not limited to eukaryotes. Indeed, in Campylobacter jejuni, a Gram negative bacterium, more than 60 of its proteins are known to be glycosylated. One of the sugars found in such glycosylated proteins is 2,4-diacetamido-2,4,6-trideoxy--d-glucopyranose, hereafter referred to as QuiNAc4NAc. The pathway for its biosynthesis, initiating with UDP-GlcNAc, requires three enzymes referred to as PglF, PglE, and PlgD. The focus of this investigation is on PglF, an NAD+-dependent sugar 4,6-dehydratase known to belong to the short chain dehydrogenase/reductase (SDR) superfamily...
October 20, 2017: Biochemistry
Zach N Nilsson, Brian L Mandella, Kakali Sen, Demet Kekilli, Michael A Hough, Pierre Moënne-Loccoz, Richard W Strange, Colin R Andrew
Nitrite coordination to heme cofactors is a key step in the anaerobic production of the signaling molecule nitric oxide (NO). An ambidentate ligand, nitrite has the potential to coordinate via the N- (nitro) or O- (nitrito) atoms in a manner that can direct its reactivity. Distinguishing nitro vs nitrito coordination, along with the influence of the surrounding protein, is therefore of particular interest. In this study, we probed Fe(III) heme-nitrite coordination in Alcaligenes xylosoxidans cytochrome c' (AXCP), an NO carrier that excludes anions in its native state but that readily binds nitrite (Kd ∼ 0...
October 20, 2017: Inorganic Chemistry
Agnese Petrini, Riccardo Pettinari, Fabio Marchetti, Claudio Pettinari, Bruno Therrien, Agustı N Galindo, Rosario Scopelliti, Tina Riedel, Paul J Dyson
A series of half-sandwich pentamethylcyclopentadienyl rhodium(III) and iridium(III) complexes [Cp*M(DBM/HDB/AVB)Cl] and [Cp*M(DBM/HDB/AVB)(PTA)][SO3CF3], where Cp* = pentamethylcyclopentadienyl, the proligands DBMH = dibenzoylmethane, HDBH = o-hydroxydibenzoylmethane, AVBH = avobenzone, and PTA = 1,3,5-triaza-7-phosphaadamantane, is reported. All the complexes were characterized by IR, (1)H and (13)C NMR spectroscopy, electrospray ionization mass spectrometry, elemental analysis, and DFT calculations. Five of the complexes have also been characterized in the solid-state by X-ray crystallography...
October 20, 2017: Inorganic Chemistry
Matthew A Marcus, Shahrouz Amini, Cayla A Stifler, Chang-Yu Sun, Nobumichi Tamura, Hans A Bechtel, Dilworth Y Parkinson, Harold S Barnard, Xiyue X X Zhang, J Q Isaiah Chua, Ali Miserez, Pupa U P A Gilbert
Parrotfish (Scaridae) feed by biting stony corals. To investigate how their teeth endure the associated contact stresses, we examine the chemical composition, nano- and micro-scale structure, and the mechanical properties of the steephead parrotfish Chlorurus microrhinos tooth. Its enameloid is a fluorapatite (Ca5(PO4)3F) biomineral with outstanding mechanical characteristics: the mean elastic modulus is 124 GPa, and the mean hardness near the biting surface is 7.3 GPa, making it among the stiffest and hardest biominerals measured; the mean indentation yield strength is above 6 GPa, and the mean fracture toughness is 2...
October 20, 2017: ACS Nano
Na Kyung Kwon, Tae Kyung Lee, Sang Kyu Kwak, So Youn Kim
Localized surface plasmon resonance (LSPR) effect relies on the shape, size, and dispersion state of metal nanoparticles and can potentially be employed in many applications such as chemical/biological sensor, optoelectronics, and photocatalyst. While complicated synthetic approaches changing shape and size of nanoparticles can control the intrinsic LSPR effect, here we show that controlling interparticle interactions with silica-coated gold nanoparticles (Au@SiO2 NPs) is a powerful approach, permitting wide range of optical bandwidth of gold nanoparticles with great stability...
October 20, 2017: ACS Applied Materials & Interfaces
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