Metal-organic frameworks (MOFs) have been recognized as compelling platforms for the development of miscellaneous applications because of their structural diversity and functional tunability. Here, ...we propose that the electrocatalytic properties could be well modified by incorporating missing linkers into the MOF. Theoretical calculations suggest the electronic structure of MOFs can be tuned by introducing missing linkers, which improves oxygen evolution reaction (OER) performance of the MOF. Inspired by these aspects, we introduced various missing linkers into a layered-pillared MOF Co
(OH)
(C
H
O
) (termed as CoBDC) to prepare missing-linker MOFs. Transmission electron microscope and synchrotron X-ray measurements confirmed that the missing linkers in the MOF could be introduced and well controlled by our strategy. The self-supported MOF nanoarrays with missing linkers of carboxyferrocene exhibit excellent OER performance with ultralow overpotential of 241 mV at 100 mA cm
. This work opens a new prospect to develop efficient MOF-based electrocatalysts by introducing missing linkers.
ShigaShield™ is a phage preparation composed of five lytic bacteriophages that specifically target pathogenic Shigella species found in contaminated waters and foods. In this study, we examined the ...efficacy of various doses (9x105-9x107 PFU/g) of ShigaShield™ in removing experimentally added Shigella on deli meat, smoked salmon, pre-cooked chicken, lettuce, melon and yogurt. The highest dose (2x107 or 9x107 PFU/g) of ShigaShield™ applied to each food type resulted in at least 1 log (90%) reduction of Shigella in all the food types. There was significant (P<0.01) reduction in the Shigella levels in all phage treated foods compared to controls, except for the lowest phage dose (9x105 PFU/g) on melon where reduction was only ca. 45% (0.25 log). The genomes of each component phage in the cocktail were fully sequenced and analyzed, and they were found not to contain any "undesirable genes" including those listed in the US Code for Federal Regulations (40 CFR Ch1). Our data suggest that ShigaShield™ (and similar phage preparations with potent lytic activity against Shigella spp.) may offer a safe and effective approach for reducing the levels of Shigella in various foods that may be contaminated with the bacterium.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
ListShield™, a commercially available bacteriophage cocktail that specifically targets Listeria monocytogenes, was evaluated as a bio-control agent for L. monocytogenes in various Ready-To-Eat foods. ...ListShield™ treatment of experimentally contaminated lettuce, cheese, smoked salmon, and frozen entrèes significantly reduced (p < 0.05) L. monocytogenes contamination by 91% (1.1 log), 82% (0.7 log), 90% (1.0 log), and 99% (2.2 log), respectively. ListShield™ application, alone or combined with an antioxidant/anti-browning solution, resulted in a statistically significant (p < 0.001) 93% (1.1 log) reduction of L. monocytogenes contamination on apple slices after 24 h at 4 °C. Treatment of smoked salmon from a commercial processing facility with ListShield™ eliminated L. monocytogenes (no detectable L. monocytogenes) in both the naturally contaminated and experimentally contaminated salmon fillets. The organoleptic quality of foods was not affected by application of ListShield™, as no differences in the color, taste, or appearance were detectable. Bio-control of L. monocytogenes with lytic bacteriophage preparations such as ListShield™ can offer an environmentally-friendly, green approach for reducing the risk of listeriosis associated with the consumption of various foods that may be contaminated with L. monocytogenes.
•ListShield™ reduced L. monocytogenes in lettuce, cheese, apples and smoked salmon.•ListShield™ reduced L. monocytogenes in frozen food entrées.•ListShield™ eliminated L. monocytogenes from naturally contaminated smoked salmon.•ListShield™ did not change the organoleptic qualities of ready to eat deli meats.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The effects of Mn 2+ doping on the structural, optical and magnetic properties of the corundum-related oxide Zn3TeO6 were investigated. Polycrystalline ceramic samples of the solid solution ...Zn3-xMnxTeO6 (0<x≤2.0) were prepared by a solid-state reaction route. Phase diagram as a function of Mn concentration indicates monoclinic (C2/c) structure for x<1.0, disproportionated mixing of both monoclinic (C2/c) and rhombohedral (R-3) structure for 1.0≤x≤1.6, and R-3 structure for x≥1.8. Moreover, when x=2.0, ZnMn2TeO6 was formed, in which the bond length of Te-O and Mn/Zn-O increased, and the Mn/ZnO6 octahedra became more distorted. Rietveld refinements of the crystal structures from the powder X-ray diffraction (XRD) data showed that the Zn/MnO6 octahedra were highly distorted in R-3 phase. With the increase of Mn 2+ doping content, the solid solution Zn3-xMnxTeO6 demonstrated not only the structure change from C2/c to R-3, but also the color evolution from light yellow to dark yellow. In optical absorption spectro
A bacteriophage cocktail (designated ECP-100) containing three Myoviridae phages lytic for Escherichia coli O157:H7 was examined for its ability to reduce experimental contamination of hard surfaces ...(glass coverslips and gypsum boards), tomato, spinach, broccoli, and ground beef by three virulent strains of the bacterium. The hard surfaces and foods contaminated by a mixture of three E. coli O157:H7 strains were treated with ECP-100 (test samples) or sterile phosphate-buffered saline buffer (control samples), and the efficacy of phage treatment was evaluated by comparing the number of viable E. coli organisms recovered from the test and control samples. Treatments (5 min) with the ECP-100 preparation containing three different concentrations of phages (10¹⁰, 10⁹, and 10⁸ PFU/ml) resulted in statistically significant reductions (P = <0.05) of 99.99%, 98%, and 94%, respectively, in the number of E. coli O157:H7 organisms recovered from the glass coverslips. Similar treatments resulted in reductions of 100%, 95%, and 85%, respectively, in the number of E. coli O157:H7 organisms recovered from the gypsum board surfaces; the reductions caused by the two most concentrated phage preparations were statistically significant. Treatment with the least concentrated preparation that elicited significantly less contamination of the hard surfaces (i.e., 10⁹ PFU/ml) also significantly reduced the number of viable E. coli O157:H7 organisms on the four food samples. The observed reductions ranged from 94% (at 120 ± 4 h posttreatment of tomato samples) to 100% (at 24 ± 4 h posttreatment of spinach samples). The data suggest that naturally occurring bacteriophages may be useful for reducing contamination of various hard surfaces, fruits, vegetables, and ground beef by E. coli O157:H7.
【Abstract】 Mixed anion compounds can generate the emergence of novel properties that differ from those with mono-type anion due to the difference of electronegativities, ionic radii, ...polarizabilities, and oxidation states between unlike anions. Abundant research has been conducted on metallic mixed-anion materials with potential application in electronics, detectors of moisture, gas sensors, electrodes for solar batteries, etc. The flux method has been widely applied for mixed-anion crystal growth, which based on metathetical reaction with appropriate metal-salts flux under mild conditions. It is meaningful to synthesize the mixed anion compounds by the flux method. Single crystals of tungsten oxychloride Li23CuW10O40Cl5 were prepared via CuCl2 flux-growth method by two steps, which using high quality and phase-pure polycrystalline Li4WO5 as precursor. The crystal structure was determined by single-crystal X-ray diffraction analysis, which indicates that Li23CuW10O40Cl5 crystallizes in P63/mcm space group（a= 1.02846（3） nm, c=1.98768（9） nm, V=1.82076（11） nm3, and Z=2）. There are crystallographically independent five Li, two W, one Cu, two Cl, and five O atoms in the unit cell, where W（1） atoms are coordinated with one Cl and five O atoms in a distorted octahedra geometry, while W（2） atoms are connected with four O atoms in a tetrahedral coordination. The Cu atoms are connected with six O atoms forming CuO6 octahedra. Thus, the crystal structure of the titled compound consists of CuO6 and W（1）O5Cl octahedra, and W（2）O4 tetrahedra. The successful synthesis of tungsten oxychloride Li23CuW10O40Cl5 through flux-growth method is meaningful for explore new mixed anion compounds in future.
The synthesis of graphyne has been considered challenging, especially when it comes to adopting new topologies and obtaining thinner layers. Herein, we report the synthesis and characterization of a ...graphyne-like porous carbon-rich network via alkyne metathesis reactions, which resulted in a sp
/sp hybridized 2D thin film structure with a layer to layer distance of 0.37 nm. This graphyne-like porous carbon-rich network is an n-type semiconductor with a low work function of 3.9 eV and a reduction potential of -0.54 V vs. SHE, which could be applied as an excellent reducing agent for metal electroless deposition. In addition, this material has a narrow pore size distribution of 2 to 4 nm, a high surface area of 675 m
g
and a large pore volume of 0.795 cm
g
favoring gas adsorption. It shows the selective absorption of CO
over N
owing to the strong affinity between CO
and the carbon-carbon triple bond.
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