Sources and preservation of organic matter in soils of the wetlands in the Liaohe (Liao River) Delta, North China

Total organic carbon, total nitrogen, delta C-13(org), delta N-15, and aliphatic and polyaromatic hydrocarbons of fifty-five soil samples collected from the coastal wetlands of the Liaohe Delta were measured, in order to determine the sources and possible preservation of organic matter (OM). The delta(15)(N) and delta C-13(org) values in the samples ranged from 3.0 parts per thousand to 9.4 parts per thousand and from -30.4 parts per thousand to -20.3 parts per thousand, respectively, implying that the OM in the soils is predominantly derived from C-3 plant. The long-chain n-alkanes had a strong odd-over-even carbon number predominance, suggesting a significant contribution from waxes of higher plants. The ubiquitous presence of unresolved complex mixture, alkylated polycylic aromatic hydrocarbons and typical biomarkers of petroleum hydrocarbons (pristane, phytane, hopanes and steranes) indicates that there is a contribution of petroleum hydrocarbons to the organic carbon pool in the wetland soils. P. australis-vegetated wetlands have strong potentials for the preservation of organic carbon in the wetlands. (C) 2013 Elsevier Ltd. All rights reserved.Total organic carbon, total nitrogen, delta C-13(org), delta N-15, and aliphatic and polyaromatic hydrocarbons of fifty-five soil samples collected from the coastal wetlands of the Liaohe Delta were measured, in order to determine the sources and possible preservation of organic matter (OM). The delta(15)(N) and delta C-13(org) values in the samples ranged from 3.0 parts per thousand to 9.4 parts per thousand and from -30.4 parts per thousand to -20.3 parts per thousand, respectively, implying that the OM in the soils is predominantly derived from C-3 plant. The long-chain n-alkanes had a strong odd-over-even carbon number predominance, suggesting a significant contribution from waxes of higher plants. The ubiquitous presence of unresolved complex mixture, alkylated polycylic aromatic hydrocarbons and typical biomarkers of petroleum hydrocarbons (pristane, phytane, hopanes and steranes) indicates that there is a contribution of petroleum hydrocarbons to the organic carbon pool in the wetland soils. P. australis-vegetated wetlands have strong potentials for the preservation of organic carbon in the wetlands. (C) 2013 Elsevier Ltd. All rights reserved

Synthesis of Fe₃C@C from Pyrolysis of Fe₃O₄-Lignin Clusters and Its Application for Quick and Sensitive Detection of PrP^Sc through a Sandwich SPR Detection Assay

The prion protein (PrPSc) has drawn widespread attention due to its pathological potential to cause prion diseases. Herein, we successfully synthesized Fe3C@C by carbonizing Fe3O4-lignin clusters, which were prepared through a facile hydrogen bonding interaction between ≡Fe-OH and hydroxyl groups of lignin. Our in-depth investigation confirmed that the composites were Fe3C@C core/shell particles. We constructed a novel sandwich surface plasmon resonance (SPR) detection assay for sensitive PrPSc detection, utilizing bare gold surface and aptamer-modified Fe3C@C (Fe3C@C-aptamer). Due to the highly specific affinity of Fe3C@C-aptamer towards PrPSc, the sandwich type SPR sensor exhibited excellent analytical performance towards the discrimination and quantitation of PrPSc. A good linear relationship was obtained between the SPR responses and the logarithm of PrPSc concentrations over a range of 0.1–200 ng/mL. The detection sensitivity for PrPSc was improved by ~10 fold compared with the SPR direct detection format. The required detection time was only 20 min. The specificity of the present biosensor was also confirmed by PrPC and other reagents as controls. This proposed approach could also be used to isolate and detect other highly pathogenic biomolecules with similar structural characteristics by altering the corresponding aptamer in the Fe3C@C conjugates

Synthesis of Magnetic Wood Fiber Board and Corresponding Multi-Layer Magnetic Composite Board, with Electromagnetic Wave Absorbing Properties

With the rapid growth in the use of wireless electronic devices, society urgently needs electromagnetic wave (EMW) absorbing material with light weight, thin thickness, wide effective absorbing band width, and strong absorption capacity. Herein, the multi-layer magnetic composite boards are fabricated by hot-pressing magnetic fiber boards and normal veneer layer-by-layer. The magnetic fibers obtained using in-situ chemical co-precipitation are used to fabricate magnetic fiber board by hot-pressing. The magnetic wave absorbing capacities of the magnetic fiber boards obtained with 72 h impregnation time exhibit strongest adsorption capacities of −51.01 dB with a thickness of 3.00 mm. It is proved that this outstanding EMW absorption property is due to the strongest dielectric loss, the optimal magnetic loss, and the dipole relaxation polarization. Meanwhile, the EMW absorbing capacities of the corresponding multi-layer composite magnetic board increases from −14.14 dB (3-layer) to −60.16 dB (7-layer). This is due to the generated multi-interfaces between magnetic fiber board and natural wood veneer in the EMW propagation direction, which significantly benefit multireflection and attenuation of the incident waves. The results obtained in this work indicate that natural wood fibers are of great potential in the fabrication of magnetic multi-layer boards treated as EMW absorbers via a low cost, green, and scalable method

Nowhere to run: oligo (p-phenylene vinylene) kills oral intracellular bacteria photodynamically

Abstract Bacterial infections pose a severe threat to human health due to the exacerbation of antibiotic resistance and intracellular bacterial infections. Research suggests that oligo(p-phenylene vinylene) (OPV), commonly employed in the manufacture of organic solar batteries, can help address this issue. This study demonstrates the ability of OPV to target and sterilize intracellular Porphyromonas gingivalis and methicillin-resistant Staphylococcus aureus (MRSA) photodynamically. Most notably, OPV specifically targets bacteria without affecting healthy cells under dark conditions. Its chemical composition includes a conjugated backbone and ionic imidazole side chains, which allow OPV to bind to cell membranes. Furthermore, dental blue light curing lamps may excite OPV. Compared with antibiotics and traditional photosensitizers, OPV proves to be a potentially superior solution to eradicate intracellular microbial infections, both in fundamental research and clinical applications