Development of a Green Alternative Procedure for the Simultaneous Separation and Quantification of Clove Oil and Its Major Bioactive Constituents

Clove buds are a good source of oil, which can be used as a food flavor and traditional Chinese medicine. To isolate clove oil and its major bioactive constituents, a green alternative procedure employing ultrasound-assisted supercritical carbon dioxide (USC–CO₂) extraction combined with gas chromatography/mass spectrometry was developed, and its performance was compared to those of conventional processes. The green USC–CO₂ process saves time, solvent, energy, and raw materials without chemical waste while achieving superior yields of clove oil and major bioactive constituents. The solubility of clove oil and fictitious solubility of eugenol in SC–CO₂ have been predicted for the first time at various temperatures (32–50 °C) and pressures (9.0–28.5 MPa). Furthermore, solubility data correlated well with three density-based models (Chrastil, Kumar–Johnston, and Bartle), and the overall average absolute relative deviations (AARD%) were 0.22, 0.92, and 4.91%, respectively. Using correlation results, we approximated the enthalpies for clove oil. The total heat of solution, heat of solvation, and heat of vaporization for clove oil were 9.83, 19.03, and −9.69 kJ/mol, respectively

Chloroplast DNA Phylogeography Reveals Repeated Range Expansion in a Widespread Aquatic Herb <i>Hippuris vulgaris</i> in the Qinghai-Tibetan Plateau and Adjacent Areas

<div><p>Background</p><p>The Qinghai-Tibetan Plateau (QTP) is one of the most extensive habitats for alpine plants in the world. Climatic oscillations during the Quaternary ice age had a dramatic effect on species ranges on the QTP and the adjacent areas. However, how the distribution ranges of aquatic plant species shifted on the QTP in response to Quaternary climatic changes remains almost unknown.</p> <p>Methodology and Principal Findings</p><p>We studied the phylogeography and demographic history of the widespread aquatic herb <i>Hippuris vulgaris</i> from the QTP and adjacent areas. Our sampling included 385 individuals from 47 natural populations of <i>H</i>. <i>vulgaris</i>. Using sequences from four chloroplast DNA (cpDNA) non-coding regions, we distinguished eight different cpDNA haplotypes. From the cpDNA variation in <i>H</i>. <i>vulgaris</i>, we found a very high level of population differentiation (<i>G</i>_ST = 0.819) but the phylogeographical structure remained obscure (<i>N</i>_ST = 0.853><i>G</i>_ST = 0.819, <i>P</i>>0.05). Phylogenetic analyses revealed two main cpDNA haplotype lineages. The split between these two haplotype groups can be dated back to the mid-to-late Pleistocene (ca. 0.480 Myr). Mismatch distribution analyses showed that each of these had experienced a recent range expansion. These two expansions (ca. 0.12 and 0.17 Myr) might have begun from the different refugees before the Last Glacial Maximum (LGM).</p> <p>Conclusions/Significance</p><p>This study initiates a research on the phylogeography of aquatic herbs in the QTP and for the first time sheds light on the response of an alpine aquatic seed plant species in the QTP to Quaternary climate oscillations.</p> </div

Phylogeny of the eight chloroplast haplotypes (A–H) detected in <i>H</i>. <i>vulgaris</i>.

<p>(<b>A</b>) Neighbor-joining clustering of the eight chloroplast haplotypes. Numbers above branches indicate the bootstrap values (>50% are shown) for NJ (Left, 1,000 replicates) and Bayesian analyses (Right). HPG: Haplogroup; (<b>B</b>) 95% plausible network of the eight chloroplast haplotypes. Each solid line represents one mutational step that interconnects two haplotypes for which parsimony is supported at the 95% level. The distribution of a certain haplotype is marked in the circles. The small open circle indicates an inferred intermediate haplotype not deteched in this investigation. The size of each circle is proportional to the haplotype frequency.</p

Low Cost Facile Synthesis of Large-Area Cobalt Hydroxide Nanorods with Remarkable Pseudocapacitance

Large-area Co­(OH)₂-based supercapacitor electrodes composed of nanotube arrays grown on a 3D nickel-foam (CONTA) electrode and sucker-like nanoporous films grown on a 3D nickel-foam (COSNP) electrode were prepared with a facile electrochemical method for applications in energy storage. These nanoporous Co­(OH)₂ electrodes were fabricated with the codeposition of Cu/Ni film on the nickel foam, then etching of Cu from the Cu/Ni layer to form Ni nanotube arrays and sucker-like Ni nanoporous layers, and further cathodic deposition of Co­(OH)₂ on the prepared nanoporous Ni substrates. The CONTA and COSNP electrodes exhibited specific capacitances of 2500 and 2900 F/g in a voltage range of 0.65 V (capacitance of the substrates deducted from the total) at 1 A/g in a three electrode cell, respectively. The COSNP electrode demonstrated an excellent supercapacitive performance with specific capacitances 1100 F/g at 1 A/g and 850 F/g at 20 A/g in a voltage range of 1.2 V in a two electrode cell. The remarkable performance of COSNP electrodes correlated with a large conversion of the Co oxidation state during the charge/discharge cycling were examined by <i>in situ</i> X-ray absorption near edge structure (XANES)

Mismatch distribution analyses and estimation of expansion time.

<p>Mismatch distribution analyses and estimation of expansion time.</p

Bayesian analyses of the divergent time (Myr) between chloroplast DNA haplotypes.

<p>Bayesian analyses of the divergent time (Myr) between chloroplast DNA haplotypes.</p

Collection localities (population codes as in Table 1) and the geographical distributions of eight chloroplast haplotypes (A–H) found in 47 populations of <i>H</i>. <i>vulgaris</i> in the Qinghai-Tibetan Plateau and neighboring areas.

<p>Collection localities (population codes as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0060948#pone-0060948-t001" target="_blank">Table 1</a>) and the geographical distributions of eight chloroplast haplotypes (A–H) found in 47 populations of <i>H</i>. <i>vulgaris</i> in the Qinghai-Tibetan Plateau and neighboring areas.</p

Details of sample locations, samples size (<i>N</i>), haplotypes and haplotype diversity (<i>h</i>) of 47 populations of <i>Hippuris vulgaris</i> surveyed for DNA sequence variation at four combined chloroplast regions.

<p>Details of sample locations, samples size (<i>N</i>), haplotypes and haplotype diversity (<i>h</i>) of 47 populations of <i>Hippuris vulgaris</i> surveyed for DNA sequence variation at four combined chloroplast regions.</p

Chloroplast DNA sequence polymorphism detected in four non-coding regions of <i>Hippuris vulgaris</i> identifying eight haplotypes (A–H).

<p>-: alignment gap; <>\raster="rg1"<>: TATAT; #: TAGAACCG; ⊚: TATTTG; §: TGTCATG.</p

Cheap, High-Performance, and Wearable Mn Oxide Supercapacitors with Urea-LiClO₄ Based Gel Electrolytes

Here we report a simple, scalable, and low-cost method to enhance the electrochemical properties of Mn oxide electrodes for highly efficient and flexible symmetrical supercapacitors. The method involving printing on a printer, pencil-drawing, and electrodeposition is established to fabricate Mn oxide/Ni-nanotube/graphite/paper hybrid electrodes operating with a low-cost, novel urea-LiClO₄/PVA as gel electrolyte for flexible solid-state supercapacitor (FSSC) devices. The Mn oxide nanofiber/Ni-nanotube/graphite/paper (MNNGP) electrodes in urea-LiClO₄/PVA gel electrolyte show specific capacitance (<i>C</i>_sp) 960 F/g in voltage region 0.8 V at 5 mV/s and exhibit excellent rates of capacitance retention more than 85% after 5000 cycles. Moreover, the electrochemical behavior of the MNNGP electrodes in urea-LiClO₄/PVA at operating temperatures 27–110 °C was investigated; the results show that the MNNGP electrodes in urea-LiClO₄/PVA exhibit outstanding performance (1100 F/g), even at 90 °C. The assembled FSSC devices based on the MNNGP electrodes in urea-LiClO₄/PVA exhibit great <i>C</i>_sp (380 F/g in potential region of 2.0 V at 5 mV/s, exhibiting superior energy density 211.1 W h/kg) and great cycle stability (less than 15% loss after 5000 cycles at 25 mV/s). The oxidation-state change was examined by in situ X-ray absorption spectroscopy. FSSC devices would open new opportunities in developing novel portable, wearable, and roll-up electric devices owing to the cheap, high-performance, wide range of operating temperature, and simple procedures for large-area fabrication