The increasing availability of genetic sequence data associated with explicit geographic and ecological information is offering new opportunities to study the processes that shape biodiversity. The ...generation and testing of hypotheses using these data sets requires effective tools for mathematical and visual analysis that can integrate digital maps, ecological data, and large genetic, genomic, or metagenomic data sets. GenGIS is a free and open-source software package that supports the integration of digital map data with genetic sequences and environmental information from multiple sample sites. Essential bioinformatic and statistical tools are integrated into the software, allowing the user a wide range of analysis options for their sequence data. Data visualizations are combined with the cartographic display to yield a clear view of the relationship between geography and genomic diversity, with a particular focus on the hierarchical clustering of sites based on their similarity or phylogenetic proximity. Here we outline the features of GenGIS and demonstrate its application to georeferenced microbial metagenomic, HIV-1, and human mitochondrial DNA data sets.
Porous polytetrafluoroethylene (PTFE) membranes were used as support material for sulfonated poly(phthalazinone ether sulfone ketone) (SPPESK)/zirconium sulfophenyl phosphate (ZrSPP)/PTFE composite ...membranes. The membranes were prepared via a spray painting method. Membranes were characterized by thermal gravimetric analysis (TGA) and scanning electron microscopy (SEM). The composite membranes exhibited good thermal stabilities. SEM micrographs confirmed that the pores of the PTFE were filled entirely with SPPESK and ZrSPP. The resulting composite membranes were mechanically durable, dimensionally stable in alternating wet/dry environments, and had lower methanol permeabilities compared with the unsupported SPPESK/ZrSPP composite membranes reported in our previous work. The water uptake of these membranes was also lower than previous SPPESK/ZrSPP composite membranes. The proton conductivity of PTFE supported SPPESK (DS 81%)/ZrSPP(10 wt%) composite membrane was as high as 0.24 S/cm at 120 °C. Thus, the composite membranes exhibited good thermal stabilities, proton conductivities, and good methanol resistance, indicating that these composite membranes could serve as effective alternative membranes for direct methanol fuel cells (DMFCs).
The Eurasian lynx (Lynx) is a medium-sized wild cat species distributed throughout Eurasia. There has been no report on Taenia species (Cestoda: Cyclophyllidea) infecting this felid in China. In this ...study, 24 tapeworms were found in two Eurasian lynxes (#1 and #2) in Xinjiang Uygur Autonomous Region (XUAR), northwestern China. Based on the number, measurements and the shape of rostellar hooks, these tapeworms belong to two Taenia species. According to the number (n = 32) and length (185–194 μm) of small hooks, the first Taenia species (n = 1, found in #2 lynx) was identified as Taenia laticollis. Phylogenetically, this species was clustered with T. laticollis genotype C (JX860623) based on its cytochrome c oxidase subunit 1 (cox1) and 16S rDNA sequences. The second Taenia species (n = 23, provisionally named as “Taenia sp.“) may represent a potentially novel tapeworm species, because of its obvious differences in the shape and lengths (174–182 μm, 98–113 μm) of large and small rostellar hooks in comparison with ten taxonomically related species. Molecular and phylogenetic analyses of the cox1 gene revealed that “Taenia sp.” has the highest rate of sequence identity (92.93%, 368/396 bp) with Taenia hydatigena reported from sheep (Ovis aries) in Slovakia. To sum up, a potentially novel tapeworm species, “Taenia sp.“, is found in Eurasian lynx. In addition, T. laticollis was found for the first time in China.
Display omitted
•Taenia. laticollis was found for the first time in China.•“Taenia sp.” is a potential novel tapeworm species found in Eurasian lynx.•Pairwise comparisons of the shape of the large rostellar hooks in Taenia sp. and the related species.
Monolayered Ni-based layered double hydroxides (LDHs) enriched with hydroxyl vacancies are synthesized and first applied in the methanol-assisted energy-saving hydrogen production system including ...independent electrolysis and photovoltaic-electrolysis. The rich hydroxyl vacancies are revealed to endow monolayered LDHs with significantly superior performance in the aspects of the activity for methanol oxidation reaction and the boosting effect for cathodic hydrogen production compared to the bulk counterparts. The theoretical and experimental results confirm that the hydroxyl vacancies can increase density of states near Fermi level of LDH (i.e. elevate electrical conductivity to form favorable charge transportation during electrocatalysis), and promote its adsorption and further cleavage for methanol, thus leading to the enhanced methanol oxidation reaction performance.
Display omitted
•Monolayered Ni-based LDHs with OH vacancies are applied in the methanol-assisted energy-saving hydrogen production.•Rich OH vacancies are revealed to endow monolayered LDHs with superior performance.•Enhancement mechanism associated with the OH vacancies existing in monolayered LDH is uncovered theoretically.
In this work, a novel catalyst is prepared by dispersing planar polyphthalocyanine cobalt (PPcCo) synthesized by polymerizing cobalt (II)-4, 4′,4″,4‴-phthalocyanine tetracarboxylic acid (TcPcCo) ...using a high surface area carbon powder (Vulcan XC 72), and then heat-treated in argon (Ar) atmosphere. The polymer and PPcCo/C catalysts are characterized systematically by a variety of methods, such as ultraviolet–visible (UV–vis) spectrophotometer, Fourier transform infrared spectrometer (FT-IR), thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscope (TEM). Results show that the PPcCo obtained is stable below 600
°C. The active site of PPcCo/C is CoN
4 in phthalocyanine ring, and the PPcCo is dispersed homogeneously on the surface of XC 72. Electrocatalytic properties and electrochemical stability of the catalysts in 0.5
mol
L
−1 H
2SO
4 are evaluated by RDE measurements. The initial potential for O
2 reduction in O
2-saturated H
2SO
4 is 0.81
V and it catalyzed O
2 reduction mainly through a four-electron process. Almost no performance degradation is observed over continuous cyclic voltammetry (CV) at 10,000 cycles (4 days). Polarization curves obtained by linear sweep voltammetry (LSV) at 200 cycles also show no change. PPcCo/C catalysts display significant electrocatalytic performance for O
2 reduction, tolerance towards methanol, and long-term stability.
Cerium sulfophenyl phosphate (CeSPP), a novel proton conductor, is prepared starting from mixtures of m-sulfophenyl phosphonic acid (msPPA) and ammonium ceric nitrate. The CeSPP samples are combined ...with poly (2, 5-benzimidazole) (ABPBI) to prepare ABPBI/CeSPP composite membranes by polyphosphoric acid (PPA) hot-pressed method. The ABPBI/CeSPP composite membranes are characterized by X-ray diffraction (XRD) and infrared spectroscopy (IR). Thermogravimetric analysis (TGA) indicates thermal stability of the composite membranes below 200 °C. Scanning electron microscopy (SEM) indicates that CeSPP particles are homogenously dispersed into the composite membranes. Ce, P and S atoms are well illustrated and uniformly distributed in composite membranes via energy-dispersive X-ray spectroscopy (EDX) analysis. The proton conductivity of membrane doped in 38 wt.% CeSPP reaches 0.14 Scm
−1 at 180 °C under 100% relative humidity.
► Cerium sulfophenyl phosphate (CeSPP) was synthesized. ► ABPBI/CeSPP membranes were prepared by polyphosphoric acid hot-pressed method. ► The composite membranes illustrated good thermal stability and mechanical properties. ► The membranes exhibited considerably high-proton conductivity at high temperature.
Ultraviolet–visible and fourier transform infrared absorption spectra indicate that polytetraphenylporphyrin Co (II) (PTPPCo) can be obtained by heat-treating 5,10,15,20-tetra ...(4-carboxyphenyl)-porphyrin Co (II) (TCPPCo) at 400 °C in argon atmosphere. Polytetraphenylporphyrin Co/C is obtained by heat treatment (HT) of TCPPCo, which is adsorbed on Vulcan XC-72 with different Co–N
4 loading, from 400 °C to 1000 °C in argon atmosphere. Catalysts are evaluated for electroreduction performances of oxygen on modified electrodes in sulfuric acid solutions. Results from electroreduction of the catalyst (HT 600 °C and 6 wt% Co–N
4 loading) show the original reduction voltage is 0.81 V versus the reversible hydrogen electrode, and the transfer electron number is 3.83. The morphology, distribution, and surface elemental analysis of the catalysts are characterized by x-ray diffraction spectroscopy and transmission electron microscopy with energy dispersive x-ray. PTPPCo can homogeneously anchor on the carbon support and withstand decomposition upon heat treatment at 600 °C. Since TCPPCo results in polymerization on XC-72, pi (π) bond increases significantly with the decrease in π-electron delocalization energy. Improved capacity in electron gain or loss is observed, and the center of electrocatalysis is clearly exposed. Thus, the activity, stability, and selectivity of the catalyst presented in this paper are proven better than those of other common catalysts.
Polybenzimidazole (PBI) based high temperature proton exchange membranes were prepared by covalent cross-linking with triglycidylisocyanurate (TGIC) and doping with highly sulfonated polyaniline ...(SPAN). Insoluble SPAN with high degree of sulfonation was synthesized as the proton conductor. SPAN was homogeneously dispersed in the PBI-TGIC matrix. The composite membranes presented good thermal, dimensional, mechanical and oxidative stability for fuel cell applications. Since TGIC was a tri-functional cross-linker, with a relatively low cross-linking degree (CLD), the mechanical strength, dimensional stability and oxidative resistance of the composite membranes were improved. The low CLD also allowed high doping level of SPAN and consequently high proton conductivity. The proton conductivity of PBI-TGIC(5%)/SPAN(50%) and PBI-TGIC(10%)/SPAN(50%) at 180°C and 100% RH was 0.13 and 0.12Scm−1, respectively. At 180°C and 50% RH, the proton conductivity of these two PEMs was 0.064 and 0.058Scm−1, respectively. At 180°C and 0% RH, the proton conductivity of them was 0.018 and 0.016Scm−1, respectively. The methanol resistance and membrane selectivity of PBI-TGIC/SPAN were also good and thus the membranes could be well applied in direct methanol fuel cells.
Display omitted
•PBI-triglycidyl isocyanurate (TGIC)/sulfonated polyaniline (SPAN) PEMs were prepared.•Water-insoluble SPAN with high sulfonation degree was doped as the proton conductor.•PEM's physicochemical property was enhanced due to the high epoxy value of TGIC.•The low cross-linking degree allowed high doping level of SPAN and high conductivity.
Spinel CoFe2O4 supported on three dimensional graphene (3DG) is prepared by hydrothermal reaction, which is denoted as CoFe2O4/3DG. The 3DG is prepared by the templated method, where coal tar pitch ...(CTP) and MgO are used as the carbon source and the template, respectively. The microstructure and composition of the resultant have been investigated by X-ray diffraction as well as X-ray photoelectron spectroscopy indicating the formation of spinel CoFe2O4 and composite of CoFe2O4/3DG. The multilayer structure of 3DG and CoFe2O4/3DG is also examined by the Raman spectra. Electrochemically, CoFe2O4/3DG shows high-performance half-wave potential is 0.80 V vs. RHE in O2-saturated 0.1 M KOH, which is compared to 20 wt% Pt/C. When evaluated for OER activity, CoFe2O4/3DG obtains a low overpotential 1.63 V vs. RHE (at j = 10 mA cm−2), which is 180 mV better than 20 wt% Pt/C. Moreover, it possesses excellent durability superior to 20 wt% Pt/C.
Display omitted
•CoFe2O4/3DG catalyst was prepared by hydrothermal reaction using 3DG as support.•CoFe2O4 is uniformly deposited on 3DG surface due to the more defects of 3D-G.•CoFe2O4/3DG with 3D porous structure was conducive to improve mass transfer.•CoFe2O4/3DG exhibited superior bi-functional catalytic activity in alkaline media.
Polymer composite membranes based on sulfonated poly(phthalazinone ether sulfone) (SPPES) and cerium sulfophenyl phosphate (CeSPP) are prepared. Three CeSPP concentrations are used: 10, 20, and ...30wt.%. The membranes are characterised by infrared spectroscopy (IR), X-ray diffraction spectroscopy, thermal gravimetric analysis, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The IR results indicate the formation of intense hydrogen bonds between CeSPP and SPPES molecules. The SEM micrographs show that CeSPP well dispersed in composite membrane. The properties of the membranes are evaluated by their water uptake, ionic exchange capacity, proton conductivity and methanol permeability. The proton conductivity of the SPPES (DS 91%)/CeSPP (30wt.%) composite membrane (I) reaches 0.384S/cm at 130°C and 100% relative humidity, which is three times more than Nafion®117. CeSPP improves the conductivity of composite membranes at a low humidity. At 105°C and 70% RH, the proton conductivity of membrane (I) is 9.1×10−2S/cm, while Nafion®117 8.8×10−3S/cm. The methanol permeability of membrane (I) is 10−8cm2/s. That is much lower than Nafion®117.
PDF
