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Xinmin Li, Yingkai Liu, Shuanghui Li, Jieqing Huang, Yuemei Wu, Dapeng Yu
Pure SnO2 and Y-doped SnO2 nanobelts were prepared by thermal evaporation at 1350 °C in the presence of Ar carrier gas (30 sccm). The samples were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), energy dispersion spectrometer (EDS), X-ray photoelectron spectrometer (XPS), UV-Vis absorption spectroscopy, Raman spectroscopy, and Fourier transform infrared spectrum (FTIR). The sensing properties of the devices based on a single SnO2 nanobelt and Y-doped SnO2 nanobelt were explored to acetone, ethanol, and ethanediol...
December 2016: Nanoscale Research Letters
Shelley D Minteer
This chapter describes methods for enzyme stabilization using micellar solutions. Micellar solutions have been shown to increase the thermal stability, as well as the pH and solvent tolerance of enzymes. This field is traditionally referred to as micellar enzymology. This chapter details the use of ionic and nonionic micelles for the stabilization of polyphenol oxidase, lipase, and catalase, although this method could be used with any enzymatic system or enzyme cascade system.
2017: Methods in Molecular Biology
Chanakan Tongsook, Johannes Niederhauser, Elena Kronegger, Grit Straganz, Peter Macheroux
The degradation of histamine catalyzed by the SAM-dependent histamine N-methyltransferase (HNMT) is critically important for the maintenance of neurological processes. Recently, two mutations in the encoding human gene were reported to give rise to dysfunctional protein variants (G60D and L208P) leading to intellectual disability. In the present study, we have expressed eight L208 variants with either apolar (L208F and L208V), polar (L208N and L208T) or charged (L208D, L208H, L208K and L208R) amino acids to define the impact of side chain variations on protein structure and function...
October 18, 2016: Biochimica et Biophysica Acta
Changliang Zhu, Jingliang Zhang, Jing Zhang, Yanhui Jiang, Zhaopeng Shen, Huashi Guan, Xiaolu Jiang
An extracellular chondroitinase ABC (ChSase ABC, EC produced by cultivating Acinetobacter sp. C26, was purified to homogeneity from the supernatant by ammonium sulfate fractionation, Q-Sepharose Fast Flow and Sephadex G-100 chromatography. The 76kDa enzyme was purified 48.09-fold to homogeneity with specific activity of 348.64U/mg, Using the chondroitin sulfate A (CS-A) as substrate, the maximal reaction rate (Vmax) and Michaelis-Menten constant (Km) of ChSase ABC were found to be 10.471μmol/min/ml and 0...
October 18, 2016: International Journal of Biological Macromolecules
Francesco Domanico, Giovanni Forte, Costanza Majorani, Oreste Senofonte, Francesco Petrucci, Vincenzo Pezzi, Alessandro Alimonti
Mercury is a heavy metal that causes serious health problems in exposed subjects. The most toxic form, i.e., methylmercury (MeHg), is mostly excreted through human hair. Numerous analytical methods are available for total Hg analysis in human hair, including cold vapour atomic fluorescence spectrometry (CV-AFS), inductively coupled plasma mass spectrometry (ICP-MS) and thermal decomposition amalgamation atomic absorption spectrometry (TDA-AAS). The aim of the study was to compare the TDA-AAS with the ICP-MS in the Hg quantification in human hair...
September 29, 2016: Journal of Trace Elements in Medicine and Biology
Payam Hayati, AliReza Rezvani, Ali Morsali, Pascal Retailleau, Roberto Centore
Nanoparticles of two new 0D, lead(II) coordination supramolecular compounds, [Pb(L)2(I)2] (1) and [Pb(L)(L(/))(H2O)]·3H2O (2), (L=1,10-phenanthroline monohydrate, L(/)=2,6-pyridinedicarboxlic acid), have been synthesized by a sonochemical process and characterized by scanning electron microscopy (SEM), field emission scanning electron microscopy (FE-SEM), X-ray powder diffraction (XRPD), FT-IR spectroscopy and elemental analyses. The single crystal X-ray data of compounds show that the Pb ion is six coordinated in both 1 and 2...
September 7, 2016: Ultrasonics Sonochemistry
Siti Baidurah, Paramasivam Murugan, Lee Joyyi, Junya Fukuda, Masaya Yamada, Kumar Sudesh, Yasuyuki Ishida
Thermally assisted hydrolysis and methylation-gas chromatography (THM-GC) in the presence of an organic alkali was validated for the compositional analysis of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(3HB-co-3HHx)] accumulated in whole bacterial cells. Recombinant Cupriavidus necator Re2058/pCB113 was grown in a batch fermentation with different concentration of palm oil and fructose in order to control the molar fraction of 3HHx in P(3HB-co-3HHx) produced in the cells. Trace amounts (30μg) of freeze-dried cells were directly subjected to THM-GC in the presence of tetramethylammonium hydroxide (TMAH) at 400°C...
October 14, 2016: Journal of Chromatography. A
Sarsvat Patel, Xiang Kou, Hao Helen Hou, Ye Bill Huang, John C Strong, Geoff G Z Zhang, Changquan Calvin Sun
Amorphous solid dispersions (ASDs) consisting of acetaminophen (APAP) and copovidone were systematically studied to identify effects of drug loading and moisture content on mechanical properties, thermal properties, and tableting behavior. ASDs containing APAP at different levels were prepared by film casting and characterized by differential scanning calorimetry and nanoindentation. The glass transition temperature (Tg) continuously decreased with increasing amount of APAP, but the hardness of ASDs was increased at a low APAP content and reduced at high APAP content...
October 18, 2016: Journal of Pharmaceutical Sciences
D Gallart-Mateu, S Armenta, M de la Guardia
The use of ion mobility spectrometry (IMS) has been evaluated as analytical methodology to detect and evaluate the occupational exposure to pesticides. The developed IMS methodology was used, in positive and negative modes, to determine the presence of pesticides in air and to evaluate possible inhalation exposures of workers and users based on active sampling on Teflon membranes and direct thermal desorption IMS. The negative IMS mode was used to determine bensulfuron, clorpyrifos, diniconazole, diuron, flutolanil and imidacloprid, while the positive mode was employed to evaluate formetanate, metalaxyl, metamitrone, metribuzin, paclobutrazol and pirimicarb...
December 1, 2016: Talanta
Natta Wiriyakun, Duangjai Nacapricha, Rattikan Chantiwas
This work presents a simple hot embossing method with a shrinking procedure to produce cross-shape microchannels on poly(methyl methacrylate) (PMMA) substrate for the fabrication of an electrophoresis chip. The proposed method employed a simple two-step hot embossing technique, carried out consecutively on the same piece of substrate to make the crossing channels. Studies of embossing conditions, i.e. temperature, pressure and time, were carried out to investigate their effects on the dimension of the microchannels...
December 1, 2016: Talanta
Heikki Aisala, Jari Sinkkonen, Marika Kalpio, Mari Sandell, Hervé This, Anu Hopia
A direct quantitative proton nuclear magnetic resonance spectroscopy method was developed for the measurement of saccharides, organic acids and amino acids in potato (Solanum tuberosum L.) tuber filaments, a complex gel-like food matrix. The method requires minimal sample preparation. It is thus a faster alternative compared to liquid sample matrices, as well as an extension to methods analyzing only selected metabolites in the sample. The samples in this study were either raw or steamed potato strips that were either measured as D2O extracts or directly without extraction or derivatization steps (in situ technique)...
December 1, 2016: Talanta
Yanan Zhang, Loong-Tak Lim
Colorimetric CO2 indicators were prepared by printing pH dyes (M-cresol purple or phenol red, tetrabutylammonium hydroxide, ethylcellulose, 1:2 ethanol:1-butanol solvent), using a commercially available thermal inkjet printer, on either cellulose paper or plastic transparency film. Indicators inks printed on the papers had higher sensitivity to CO2, greater color change, and more producible than those printed on plastic film. Varying the print intensities of the two pH dyes resulted in multiplexed indicators with tunable sensitivity and expanded detection concentration range towards CO2...
December 1, 2016: Talanta
Sayed-Rzgar Hosseini, Andreas Wagner
BACKGROUND: Biological systems are rife with examples of pre-adaptations or exaptations. They range from the molecular scale - lens crystallins, which originated from metabolic enzymes - to the macroscopic scale, such as feathers used in flying, which originally served thermal insulation or waterproofing. An important class of exaptations are novel and useful traits with non-adaptive origins. Whether such origins could be frequent cannot be answered with individual examples, because it is a question about a biological system's potential for exaptation...
October 21, 2016: BMC Systems Biology
K Raafat, M Wurglics, M Schubert-Zsilavecz
Prunella vulgaris L. (Lamiaceae) (PV) is a herbaceous plant traditionally utilized in management of diabetes and it has immunomodulatory activity. In this study, acute and subchronic antidiabetic, in-vivo antioxidant and antinociceptive effects of PV were evaluated in alloxan-induced type 1 diabetes (T1D) in a mouse model. Bio-guided fractionation, isolation, RP-HPLC, and (1)H and (13)C NMR identification of the active components responsible for PV effects were determined. RP-HPLC analysis showed that PV contained rosmarinic acid (RA) 4...
October 18, 2016: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
Shobini Jayaraman, Jose Luis Sánchez-Quesada, Olga Gursky
Lipids in the body are transported via lipoproteins that are nanoparticles comprised of lipids and amphipathic proteins termed apolipoproteins. This family of lipid surface-binding proteins is over-represented in human amyloid diseases. In particular, all major proteins of high-density lipoproteins (HDL), including apoA-I, apoA-II and serum amyloid A, can cause systemic amyloidoses in humans upon protein mutations, post-translational modifications or overproduction. Here, we begin to explore how the HDL lipid composition influences amyloid deposition by apoA-I and related proteins...
October 18, 2016: Biochimica et Biophysica Acta
Florian A Busch, Rowan F Sage
The biochemical model of C3 photosynthesis by Farquhar, von Caemmerer and Berry (FvCB) assumes that photosynthetic CO2 assimilation is limited by one of three biochemical processes that are not always easily discerned. This leads to improper assessments of biochemical limitations that limit the accuracy of the model predictions. We use the sensitivity of rates of CO2 assimilation and photosynthetic electron transport to changes in O2 and CO2 concentration in the chloroplast to evaluate photosynthetic limitations...
October 21, 2016: New Phytologist
Nitzan Krinsky, Maya Kaduri, Janna Shainsky-Roitman, Mor Goldfeder, Eran Ivanir, Itai Benhar, Yuval Shoham, Avi Schroeder
Cell-free protein synthesis (CFPS) systems are important laboratory tools that are used for various synthetic biology applications. Here, we present a simple and inexpensive laboratory-scale method for preparing a CFPS system from E. coli. The procedure uses basic lab equipment, a minimal set of reagents, and requires less than one hour to process the bacterial cell mass into a functional S30-T7 extract. BL21(DE3) and MRE600 E. coli strains were used to prepare the S30-T7 extract. The CFPS system was used to produce a set of fluorescent and therapeutic proteins of different molecular weights (up to 66 kDa)...
2016: PloS One
Leandro R F Lima, Alexis R Hernández, Felipe A Pinheiro, Caio Lewenkopf
Based on the investigation of the multi-terminal conductance of a system composed of two graphene nanoribbons, in which one is on top of the other and rotated by [Formula: see text], we propose a setup for a 50/50 electronic beam splitter that neither requires large magnetic fields nor ultra low temperatures. Our findings are based on an atomistic tight-binding description of the system and on the Green function method to compute the Landauer conductance. We demonstrate that this system acts as a perfect 50/50 electronic beam splitter, in which its operation can be switched on and off by varying the doping (Fermi energy)...
October 21, 2016: Journal of Physics. Condensed Matter: An Institute of Physics Journal
M Barbagallo, A Musumarra, L Cosentino, E Maugeri, S Heinitz, A Mengoni, R Dressler, D Schumann, F Käppeler, N Colonna, P Finocchiaro, M Ayranov, L Damone, N Kivel, O Aberle, S Altstadt, J Andrzejewski, L Audouin, M Bacak, J Balibrea-Correa, S Barros, V Bécares, F Bečvář, C Beinrucker, E Berthoumieux, J Billowes, D Bosnar, M Brugger, M Caamaño, M Calviani, F Calviño, D Cano-Ott, R Cardella, A Casanovas, D M Castelluccio, F Cerutti, Y H Chen, E Chiaveri, G Cortés, M A Cortés-Giraldo, S Cristallo, M Diakaki, C Domingo-Pardo, E Dupont, I Duran, B Fernandez-Dominguez, A Ferrari, P Ferreira, W Furman, S Ganesan, A García-Rios, A Gawlik, T Glodariu, K Göbel, I F Gonçalves, E González-Romero, E Griesmayer, C Guerrero, F Gunsing, H Harada, T Heftrich, J Heyse, D G Jenkins, E Jericha, T Katabuchi, P Kavrigin, A Kimura, M Kokkoris, M Krtička, E Leal-Cidoncha, J Lerendegui, C Lederer, H Leeb, S Lo Meo, S J Lonsdale, R Losito, D Macina, J Marganiec, T Martínez, C Massimi, P Mastinu, M Mastromarco, A Mazzone, E Mendoza, P M Milazzo, F Mingrone, M Mirea, S Montesano, R Nolte, A Oprea, A Pappalardo, N Patronis, A Pavlik, J Perkowski, M Piscopo, A Plompen, I Porras, J Praena, J Quesada, K Rajeev, T Rauscher, R Reifarth, A Riego-Perez, P Rout, C Rubbia, J Ryan, M Sabate-Gilarte, A Saxena, P Schillebeeckx, S Schmidt, P Sedyshev, A G Smith, A Stamatopoulos, G Tagliente, J L Tain, A Tarifeño-Saldivia, L Tassan-Got, A Tsinganis, S Valenta, G Vannini, V Variale, P Vaz, A Ventura, V Vlachoudis, R Vlastou, J Vollaire, A Wallner, S Warren, M Weigand, C Weiß, C Wolf, P J Woods, T Wright, P Žugec
The energy-dependent cross section of the ^{7}Be(n,α)^{4}He reaction, of interest for the so-called cosmological lithium problem in big bang nucleosynthesis, has been measured for the first time from 10 meV to 10 keV neutron energy. The challenges posed by the short half-life of ^{7}Be and by the low reaction cross section have been overcome at n_TOF thanks to an unprecedented combination of the extremely high luminosity and good resolution of the neutron beam in the new experimental area (EAR2) of the n_TOF facility at CERN, the availability of a sufficient amount of chemically pure ^{7}Be, and a specifically designed experimental setup...
October 7, 2016: Physical Review Letters
Mar Bastero-Gil, Arjun Berera, Rudnei O Ramos, João G Rosa
We show that inflation can naturally occur at a finite temperature T>H that is sustained by dissipative effects, when the inflaton field corresponds to a pseudo Nambu-Goldstone boson of a broken gauge symmetry. Similar to the Little Higgs scenarios for electroweak symmetry breaking, the flatness of the inflaton potential is protected against both quadratic divergences and the leading thermal corrections. We show that, nevertheless, nonlocal dissipative effects are naturally present and are able to sustain a nearly thermal bath of light particles despite the accelerated expansion of the Universe...
October 7, 2016: Physical Review Letters
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