ABSTRACT
Oceanic uptake and storage of anthropogenic CO2 (CANT) are regulated by ocean circulation and ventilation. To decipher the storage and redistribution of CANT in the western North Pacific, where a major CANT sink develops, we investigated the water column carbonate system, dissolved inorganic radiocarbon and ancillary parameters in May and August 2018, spanning the Kuroshio Extension (KE, 35-39 °N), Kuroshio Recirculation (KR, 27-35 °N) and subtropical (21-27 °N) zones. Water column CANT inventories were estimated to be 40.5 ± 1.1 mol m-2 in the KR zone and 37.2 ± 0.9 mol m-2 in the subtropical zone. In comparison with historical data obtained in 2005, relatively high rates of increase of the CANT inventory of 1.05 ± 0.20 and 1.03 ± 0.12 mol m-2 yr-1 in the recent decade were obtained in the KR and subtropical zones, respectively. Our water-mass-based analyses suggest that formation and transport of subtropical mode water dominate the deep penetration, storage, and redistribution of CANT in those two regions. In the KE zone, however, both the water column CANT inventory and the decadal CANT accumulation rate were small and uncertain owing to the dynamic hydrology, where the naturally uplifting isopycnal surfaces make CANT penetration relatively shallow. The findings of this study improve the understanding of the spatiotemporal variations of CANT distribution, storage, and transport in the western North Pacific.
ABSTRACT
We report on a supramolecular sensor array using fluorogenic peptide probes and graphene oxide that can target glycoproteins on a viral caspid, facilitating the differentiation of ebola virus from marburg virus and receptor-extensive vesicular stomatitis virus using principal component analysis.
Subject(s)
Biosensing Techniques , Capsid Proteins/chemistry , Ebolavirus/isolation & purification , Fluorescent Dyes/chemistry , Glycoproteins/chemistry , Graphite/chemistry , Peptides/chemistry , Marburgvirus/isolation & purification , Vesiculovirus/isolation & purificationABSTRACT
The cyclotides are a family of cyclic "mini" proteins that occur in Violaceae, Rubiaceae and Cucurbitaceae plant families and contain a head-to-tail cyclic backbone and a cystine knot arranged by three disulfide bonds. To study the natural cyclotides of V tianshanica, dried herb was extracted with 50% ethanol, and the concentrated aqueous extract was subjected to a solvent-solvent partitioning between water and hexane, ethyl acetate and n-butanol, separately. The n-butanol extract containing cyclotides was subjected to column chromatography over Sephadex LH-20, eluted with 30% methanol. The subfractions were directly reduced by DTT and analyzed by reverse-phase HPLC. The peaks with different retention times were shown on the profile of RP-HPLC and collected. The cyclotides were speculated based on masses range from 3 000 to 3 500 Da. The purified cyclotides were reduced with DTT, alkylated with iodoacetamide, and then were cleaved with endoproteinase Glu-C, endoproteinase Lys-C and Trypsin, separately. The digested peptides were purified on RP-HPLC and analyzed on MALDI TOF/TOF analyzer. A new cyclotide, cycloviolacin T1 and a reported cyclotide varv E were systemically determined using MALDI TOF/TOF system. So the method for the isolation and characterization of cyclotides was quickly built up in succession.
Subject(s)
Cyclotides/isolation & purification , Viola/chemistry , Amino Acid Sequence , Chromatography, High Pressure Liquid , Cyclotides/chemistry , Molecular Sequence Data , Molecular Structure , Plants, Medicinal/chemistry , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Tandem Mass SpectrometryABSTRACT
The composition and distribution of aliphatic (n-alkanes) and polyaromatic hydrocarbons (PAHs) were measured for the surface sediments collected at 25 sites from Jiaozhou Bay, Qingdao, China. Total n-alkanes and PAH concentrations ranged from 0.5 to 8.2 microg/gdw and 0.02 to 2.2 microg/gdw, respectively, and the distribution of both n-alkanes and PAHs showed large spatial variations in the bay. The distribution of PAHs in the sediments was predominated by the three or more ring compounds. High hydrocarbon levels were generally found in the areas associated with high anthropogenic impact and port activities in the bay. The calculated hydrocarbon indexes suggest that petroleum contamination was the main source of n-alkanes, while both pyrolytic and petrogenic sources contributed PAHs to the surface sediments of Jiaozhou Bay. In comparison to other polluted coastal sediments, the level of contamination from both aliphatic hydrocarbons and PAHs in Jiaozhou Bay sediments is relatively low at the present time.
