bluuebunny/crossref_metadata_2025_split huggingface dataset:
A bioinspired polydopamine approach toward the preparation of gold‐modified magnetic nanoparticles for the magnetic solid‐phase extraction of steroids in multiple samples
Authors: An Xuehan , Chai Weibo , Deng Xiaojuan , Chen Hui , Ding Guosheng 
Published: May 2018

AbstractIn this work, a simple, facile, and sensitive magnetic solid‐phase extraction method was developed for the extraction and enrichment of three representative steroid hormones before high‐performance liquid chromatography analysis. Gold‐modified Fe3O4 nanoparticles, as novel magnetic adsorbents, were prepared by a rapid and environmentally friendly procedure in which polydopamine served as the reductant as well as the stabilizer for the gold nanoparticles, thus successfully avoiding the use of some toxic reagents. To obtain maximum extraction efficiency, several significant factors affecting the preconcentration steps, including the amount of adsorbent, extraction time, pH of the sample solution, and the desorption conditions, were optimized, and the enrichment factors for three steroids were all higher than 90. The validity of the established method was evaluated and good analytical characteristics were obtained. A wide linearity range (0.8–500 μg/L for all the analytes) was attained with good correlation (R2 ≥ 0.991). The low limits of detection were 0.20–0.25 μg/L, and the relative standard deviations ranged from 0.83 to 4.63%, demonstrating a good precision. The proposed method was also successfully applied to the extraction and analysis of steroids in urine, milk, and water samples with satisfactory results, which showed its reliability and feasibility in real sample analysis.
Soil respiration versus vegetation degradation under the influence of three grazing regimes in the Songnen Plain
Authors: Li Qiang , Zhou Dao‐Wei 
Published: May 2018

AbstractUnderstanding the effects of ongoing vegetation degradation (due to grazing pressure) on soil respiration provides a basis for managing grazing to improve sustainability of grassland ecosystems in the context of climate change. In a 2‐year field experiment in a meadow ecosystem, vegetation, soil properties, and root and microbial respiration of 2 dominant communities (Leymus chinensis and Chloris virgata) were examined along a vegetation degradation sequence caused by varying grazing pressures. Aboveground biomass, belowground net primary productivity, litter mass, and microbial biomass carbon significantly decreased as ground cover was reduced. For 2 community types, from light degradation to severe degradation (SD), soil organic carbon (SOC), soil total nitrogen, and total phosphorus concentrations decreased by 14.1–15.4%, 10.9–12.3%, and 10.7–11.9%, respectively; and soil bulk density and pH increased by 9.1–9.3% and 4.6–5.2%, respectively. Over 2 years, from light degradation to SD in 2 communities, annual mean root and microbial respiration rate significantly decreased by 35.9–43.5% and 28–34.4%, respectively. Root respiration was more sensitive to vegetation degradation in C. virgata communities compared with L. chinensis communities. However, temperature sensitivity (Q10) for root and microbial respiration did not significantly change as vegetation degraded. These results indicated that (a) vegetation degradation could drive significant soil degradation in this meadow; (b) vegetation degradation restrained soil CO2 efflux, but more largely decreased biomass carbon input into soil, which finally reduced SOC concentration; and (c) vegetation degradation would not change the response of soil CO2 efflux to climate change. To increase SOC storage and maintain grassland sustainability, grazing exclusion was suggested for restoring vegetation in SD sites, with a stocking rate < 2 sheep·ha−1 or rotational grazing recommended. Finally, overseeding with L. chinensis and legumes should enhance forage and livestock production, and soil carbon and nitrogen sequestration, thus preserving grassland sustainability in this meadow ecosystem.
The molecular dynamics of soil humus as a function of tillage
Authors: Drosos Marios , Piccolo Alessandro 
Published: May 2018

AbstractSoil degradation processes due to intensified agriculture may be counteracted by an extended knowledge on soil humus dynamics at molecular level. Here, we show that the molecular composition of the soil Humeome changes substantially after 1 and 3 years of conventional tillage under maize cropping. Application of Humeomics sequential chemical fractionation not only separated from soil more than twice the organic carbon extracted by traditional methods, but also enabled to identify 10 times more molecular structures using GC–MS and high‐resolution ESI‐Orbitrap‐MS. The fine molecular description of the soil Humeome revealed a decrease of soil organic matter (SOM) hydrophobic protection with prolonged tillage and a potential loss of small nitrogen‐rich compounds. We showed for the first time an abundance of heterocyclic nitrogen compounds that are persistent in SOM due to a covalent binding to soil iron. The formation of organo‐Fe complexes appeared not only as a major mechanism of molecular stabilization of SOC but also as an adsorption substrate for other nitrogen‐rich soil components. The detailed molecular insight of SOM composition reached by Humeomics may become the key to develop new technologies for the control of soil carbon.
Groundwater vulnerability assessment in degraded coal mining areas using the AHP–Modified DRASTIC model
Authors: Karan Shivesh Kishore , Samadder Sukha Ranjan , Singh Vivek 
Published: May 2018

AbstractExtensive coal mining results in ecological upheaval. Mining activities such as excavation and dumping of overburden convert land into new habitats, which completely degrades the soil structure. Adverse impacts of coal mining activities on water resources have been reported from several such regions. This study focusses on the assessment of groundwater vulnerability due to land degradation in coal mining areas. Three techniques were used to study the groundwater vulnerability: (a) the original DRASTIC overlay and index based model, (b) a modified DRASTIC model developed by adding land use and distance from lineament parameters, and (c) a model developed using analytic hierarchy process to optimise the rates and weights of the modified DRASTIC parameters. The groundwater vulnerability assessment models were validated by comparing the analysed groundwater samples data of the region and then by comparing with the computed overall water quality index for each sampling site. The results showed that groundwater vulnerability assessment in coal mining areas can be significantly improved. The best results were observed using an analytic hierarchy process–Modified DRASTIC model, which showed the highest positive significant (p < .01) correlation (r = .94) with the water quality index. Spatial distribution results revealed critical impact of land degradation due to coal mining on groundwater, as nearly 24% of the entire study area lied in the high to very high vulnerable zones, most of which are located in the vicinity of mining areas. This study will help in better water management practices in coal mining areas.
The Red Sea Simulator: A high‐precision climate change mesocosm with automated monitoring for the long‐term study of coral reef organisms
Authors: Bellworthy Jessica , Fine Maoz 
Published: May 2018

AbstractExperimental systems that enable the controlled perturbation of environmental parameters toward future scenarios are in high demand and becoming increasingly advanced. Herein, we describe the design and assess the performance of a large‐scale, flow‐through, mesocosm system. Located in the northern Gulf of Aqaba, the Red Sea simulator (RSS) was constructed in order to expose local coral reef organisms to future ocean scenarios. Seawater temperature and pH are typically set to a delta from incoming seawater readings and thus follow the diel range. This is achieved through automated monitoring (sensor‐carrying robot) and feedback system and a remote‐controlled user interface. Up to six different temperatures and four pH scenarios can be concomitantly operated in a total of 80 experimental aquaria. In addition, the RSS currently facilitates the manipulation of light intensity, light spectra, nutrient concentration, flow, and feeding regime. Monitoring data show that the system performs well; meeting the user‐defined environmental settings. A variety of reef organisms have been housed in the system for several months. Brooding reef building and soft coral species maintained in the simulator for many months have released planulae in synchrony with field colonies. This system boasts a high degree of replication, potential for multistressor manipulation, typical physiochemical environmental variability, and remotely controlled monitoring and data acquisition. These aspects greatly enhance our ability to make ecologically relevant performance assessments in a changing world.
Embedding and slicing of intact in situ collected marine snow
Authors: Flintrop Clara M. , Rogge Andreas , Miksch Sebastian , Thiele Stefan , Waite Anya M. , Iversen Morten H. 
Published: April 2018

AbstractThe biological carbon pump is largely driven by the formation and sinking of marine snow. Because of their high organic matter content, marine snow aggregates are hotspots for microbial activity, and microbial organic matter degradation plays an important role in the attenuation of carbon fluxes to the deep sea. Our inability to examine and characterize microscale distributions of compounds making up the aggregate matrix, and of possible niches inside marine snow, has hindered our understanding of the basic processes governing marine carbon export and sequestration. To address this issue, we have adapted soft‐embedding and sectioning to study the spatial structure and components of marine aggregates at high resolution. Soft‐embedding enables rapid quantitative sampling of undisturbed marine aggregates from the water column and from sediment traps, followed by spatially resolved staining and characterization of substrates of the aggregate matrix and the microorganisms attached to it. Particular strengths of the method include in situ embedding in sediment traps and successful fluorescence in situ hybridization (FISH)‐probe labeling, supporting studies of microbial diversity and ecology. The high spatial resolution achieved by thin‐sectioning of soft‐embedded aggregates offers the possibility for improved understanding of the composition and structure of marine snow, which directly influence settling velocity, microbial colonization and diversity, degradation rates, and carbon content. Our method will help to elucidate the small‐scale processes underlying large‐scale carbon cycling in the marine environment, which is especially relevant in the context of rising anthropogenic CO2 emissions and global change.
Rapid Determination of the Chemical Composition of Ethylene/Butadiene Copolymers Using FTIR Spectroscopy and Chemometrics
Authors: Boyron Olivier , Macqueron Benoît , Taam Manel , Thuilliez Julien , Boisson Christophe 
Published: May 2018

AbstractFourier transform infrared spectroscopy by attenuated total reflection (ATR‐FTIR), combined with the partial least square (PLS) method provides a fast characterization of ethylene/butadiene copolymers' intricate composition. The PLS regression method is constructed to quantify ethylene, 1,2‐butadiene (vinyl), trans‐1,4‐butadiene, and 1,2‐cyclohexane units in the copolymer. These rings are formed by intramolecular cyclization during polymerization. The performance of PLS models is evaluated by comparing the result obtained by 13C NMR and the model for three unknown samples. It is shown that the proposed method allows to accurately estimate the chemical composition of ethylene/butadiene copolymers in a much shorter time than NMR.
Fabrication of High‐Performance Cationic UV Curable Cycloaliphatic Epoxy/Silicone Hybrid Coatings
Authors: Zhu Qingqing , Liang Liyan , Du Xiangxiang , Xiao Fei , Guo Yuyue , Shi Jun , Wu Kun , Lu Mangeng 
Published: May 2018

AbstractA series of cycloaliphatic epoxy acrylate prepolymer poly (METHB‐co‐MMA‐co‐BA) (MMB) and an epoxycyclohexyl‐modified polydimethylsiloxane (PDMS‐VCH) are prepared to fabricate hybrid coatings. The curing process, surface performance, mechanical properties, and thermal behavior are investigated by real‐time Fourier transform infrared (FT‐IR), contact angle measurements, tensile test, thermogravimetric analyzer (TGA), and differential scanning calorimeter (DSC). For the same photoinitiator (PI) concentration, both the epoxy value and the amount of PDMS‐VCH negatively affect the UV‐curing process. The contact angle of hybrid coatings increases by almost 12° with 4 wt% PDMS‐VCH's addition. The increasing ratio of soft acrylate segment can strengthen the toughness of materials markedly. Besides, thermal stability is enhanced with the increasing of epoxy value, while slight changes are found with the addition of PDMS‐VCH. Based on these properties, the hybrid coatings can be applied in various fields, including protection, decoration, and other displayed fields.
Segmental Mobility Studies of Poly(N‐isopropyl acrylamide) Interactions with Gold Nanoparticles and Its Use as a Thermally Driven Trapping System
Authors: Swift Thomas , Rehman Kiran , Surtees Alexander , Hoskins Richard , Hickey Stephen G. 
Published: May 2018

AbstractThermal desolvation of poly(N‐isopropylacrylamide) (PNIPAM) in the presence of a low concentration of gold nanoparticles incorporates the nanoparticles resulting in suspended aggregates. By covalently incorporating <1% acenaphthylene into the polymerization feed this copolymer is enabled to be used as a model to study the segmental mobility of the PNIPAM backbone in response to gold nanoparticles both below and above the desolvation temperature, showing that there is a physical conformational rearrangement of the soluble polymer at ultralow nanoparticle loadings, indicating low affinity interactions with the nanoparticles. Thermal desolvation is capable of extracting >99.9% of the nanoparticles from their solutions and hence demonstrates that poly(N‐isopropylacrylamide) can act as an excellent scrubbing system to remove metallic nanomaterial pollutants from solution.
Reconfigurable Polymer Shells on Shape‐Anisotropic Gold Nanoparticle Cores
Authors: Kim Juyeong , Song Xiaohui , Kim Ahyoung , Luo Binbin , Smith John W. , Ou Zihao , Wu Zixuan , Chen Qian 
Published: May 2018

AbstractReconfigurable hybrid nanoparticles made by decorating flexible polymer shells on rigid inorganic nanoparticle cores can provide a unique means to build stimuli‐responsive functional materials. The polymer shell reconfiguration has been expected to depend on the local core shape details, but limited systematic investigations have been undertaken. Here, two literature methods are adapted to coat either thiol‐terminated polystyrene (PS) or polystyrene‐poly(acrylic acid) (PS‐b‐PAA) shells onto a series of anisotropic gold nanoparticles of shapes not studied previously, including octahedron, concave cube, and bipyramid. These core shapes are complex, rendering shell contours with nanoscale details (e.g., local surface curvature, shell thickness) that are imaged and analyzed quantitatively using the authors' customized analysis codes. It is found that the hybrid nanoparticles based on the chosen core shapes, when coated with the above two polymer shells, exhibit distinct shell segregations upon a variation in solvent polarity or temperature. It is demonstrated for the PS‐b‐PAA‐coated hybrid nanoparticles, the shell segregation is maintained even after a further decoration of the shell periphery with gold seeds; these seeds can potentially facilitate subsequent deposition of other nanostructures to enrich structural and functional diversity. These synthesis, imaging, and analysis methods for the hybrid nanoparticles of anisotropically shaped cores can potentially aid in their predictive design for materials reconfigurable from the bottom up.
Polyhistidine‐Based Metal Coordination Hydrogels with Physiologically Relevant pH Responsiveness and Enhanced Stability through a Novel Synthesis
Authors: Tang Quan , Zhao Dinglei , Zhou Qiang , Yang Haiyang , Peng Kang , Zhang Xingyuan 
Published: May 2018

AbstractUtilizing the abnormal physiological conditions of disease tissues can result in a site‐specific functionality with high control and efficiency of stimuli‐responsive hydrogels. Here, a physiologically relevant pH‐responsive and self‐healing hydrogel is reported based on coordination between Ni2+ and four‐arm poly(ethylene glycol)‐b‐polyhistidine (4PEG‐PHis) that is synthesized by a novel and facile PHis preparation method using amino‐terminalized four‐arm PEG as the macroinitiator. Reversible PHisNi coordination bonds endow the hydrogel with multistimuli‐triggered sol‐gel transition (physiologically relevant pH, EDTA) and self‐healing properties. It is also demonstrated that 4PEG‐PHis could be used as an injectable hydrogel in phosphate buffer (pH 7.4), and excellent stability in neutral buffer via multivalent coordination is shown, thus indicating its potential applications in controlled drug release systems.
Increasing Iodine Concentrations during Landlocked Fall Chinook Salmon Egg Disinfection Decrease Bacterial Numbers with No Impact on Egg Survival
Authors: Huysman Nathan , Bergmann David , Nero Patrick , Larson Jesse , Sabrowski Valerie , Barnes Michael E 
Published: May 2018

Abstract
Egg disinfection is an important practice that prevents potential disease transfer, but currently allowable disinfection regimes do not completely eliminate external egg membrane microbes. In this experiment, newly fertilized and water-hardened landlocked fall Chinook Salmon Oncorhynchus tshawytscha eggs were submersed for 10 min in povidone-iodine solutions containing 0, 100, 200, and 400 mg/L active iodine. External egg bacterial numbers (CFUs) were quantified after each disinfection treatment, and egg survival (%) was calculated at the eyed stage. All of the disinfection treatments significantly reduced CFUs compared with untreated controls. However, eggs from the 400-mg/L iodine treatment had significantly lower CFUs (2.20 ± 0.59 [mean ± SE]) than the 100-mg/L (10.43 ± 8.01) and 200-mg/L (8.10 ± 1.51) treatments. Percent survival was not significantly different among any of the treatments; survival was 18.86 ± 5.17%, 19.17 ± 4.76%, and 20.16 ± 5.27% in the eggs subjected to 100 mg/L, 200 mg/L, and 400 mg/L iodine, respectively. These results indicate that 10-min treatments of 400 mg/L active iodine on landlocked fall Chinook Salmon eggs provide the most microbial reduction with no effect on subsequent egg survival.
Sauger and Walleye Year-Class Formation in the Lower Wisconsin River, 1987–2016
Authors: Lyons John , Oele Daniel L. 
Published: May 2018

Abstract
Sauger Sander canadense and Walleye S. vitreus support important fisheries throughout much of northern North America, but their management is complicated by highly variable reproductive success from year to year. We analyzed patterns of juvenile abundance in the lower Wisconsin River, a large, lowland river in the upper Midwestern United States, to better understand the formation of strong and weak year-classes. Annual standardized fall electrofishing catches of age-0 Saugers and age-0 Walleyes fluctuated greatly from 1987 to 2016. Few significant correlations existed between catches of age-0 fish of either species and environmental and biological variables, although strong and weak year-classes were often synchronous between Walleye and Sauger. Random forest models indicated that age-0 Sauger catches were positively related to age-0 Walleye catches and negatively related to the CV (100·SD/mean) of daily air temperatures during the growing season and catches of Largemouth Bass Micropterus salmoides. Age-0 Walleye catches were positively related to age-0 Sauger catches and negatively related to Largemouth Bass catches and the CV in daily river flows during the growing season. However, these models explained little of the variation in age-0 abundance over the 30 years of data. Excluding the 1987 Walleye year-class, catches of age-0 Saugers and age-0 Walleyes were significantly correlated with respective catches of age-1 fish 1 year later and age-2 fish 2 years later, indicating that year-class strength was largely set in the first year of life and could be indexed by standardized fall electrofishing. Because a full understanding of the causes of year-class formation remains elusive, continued annual monitoring of age-0 Sauger and age-0 Walleye abundance will benefit the management of the recreational fishery of the lower Wisconsin River.
Time and temperature dependence of radiofrequency ablation in the human placenta
Authors: Phithakwatchara Nisarat , Makarasen Preechaya , Nawapun Katika , Hanamornroongruang Suchanan , Viboonchart Sommai , Wataganara Tuangsit 
Published: May 2018

AbstractObjectiveThe objective of the study is to compare radiofrequency (RF) effects on fresh placentae with varying levels of sustained time (Ts) and degrees of target temperature (°t).MethodA total of 108 pieces of fresh placentae were coagulated with a 2‐cm RF needle at 60 W in an organ bath. The vertical and horizontal diameters (Vd, Hd) of tissue coagulation visualized by ultrasound were measured. The impacts of 12 different Ts‐°t combinations on the ablation size ascertained on pathological examination (Vdp, Hdp) were compared using 2‐way ANOVA. The agreement between sonographic and pathological findings was assessed using Bland‐Altman analysis.ResultsConsiderable changes in the Vdp and Hdp were associated with increasing the Ts and °t. The impact of RF on tissue coagulation was greatest when the °t was set at 100°C, with further destruction as the Ts progressed to 7 minutes of exposure. The ablation size estimated by ultrasound exhibited an overestimation by an average of 5.65% and 21.02% for Vd and Hd, respectively.ConclusionA prolonged Ts at a higher °t contributes to progressive placental tissue destruction by RF, with maximum destruction at 100°C for 7 minutes in an ex vivo nonperfused placenta. Tissue injury that is apparent on ultrasound may extend beyond pathological damage.