bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recent strategies to enhance the performance of polymer monoliths for analytical separations
Authors: Maya Fernando , Paull Brett 
Published: February 2019

AbstractThis review summarizes recent developments made in the incorporation of functional materials into organic polymer monoliths, together with new monolithic forms and formats, which enhance their application as supports and stationary phase materials for sample preparation and chromatographic separations. While polymer monoliths are well‐known supports for the separation of large molecules, recent developments have been made to improve their features for the separation of small molecules. The selectivity and performance of organic polymer monoliths has been improved by the incorporation of different materials, such as metal‐organic frameworks, covalent organic frameworks, or other types of nanostructured materials (carbon nanohorns, nanodiamonds, polyoxometalates, layered double hydroxides, or attapulgite). The surface area of polymer monoliths has been significantly increased by polymer hypercrosslinking, resulting in increased efficiency when applied to the separation of small molecules. In addition, recent exploration of less conventional supports for casting polymer monoliths, including photonic fibres and 3D printed materials, has opened new avenues for the applications of polymer monoliths in the field of separation science. Recent developments made in these topics are covered, focusing on the strategies followed by the authors to prepare the polymer monoliths and the effect of these modifications on the developed analytical applications.
Magnetic solid‐phase extraction of benzoylurea insecticides in tea samples with Fe3O4‐hyperbranched polyester magnetic composite as sorbent
Authors: Liu Chaoran , Liu Xinya , Marriott Philip J. , Qian Heng , Meng Zilin , Yang Zhirong , Lu Runhua , Gao Haixiang , Zhou Wenfeng 
Published: February 2019

AbstractIn this work, a method for the analysis of benzoylurea insecticides, including hexaflumuron, flufenoxuron, lufenuron and chlorfluazuron, in tea samples by high‐performance liquid chromatography with Fe3O4‐hyperbranched polyester nanocomposite as the adsorbent for magnetic solid‐phase extraction was developed. The magnetic nanocomposite was prepared and characterized by infrared spectroscopy, vibrating sample magnetometry, and scanning electron microscopy. The as‐prepared nanocomposite was used as a sorbent for the extraction and preconcentration of pesticide residues in tea samples. The extraction and desorption conditions, including mass ratios of raw materials, amount of sorbent, pH value, extraction time, and desorption time, were investigated. Under the final conditions chosen for the analysis, good linearity was obtained for all the tested compounds, with R2 values of at least 0.9979. The limits of detection were determined in the range of 0.15–0.3 μg/L. The recovery obtained from the analysis of tea samples with various spiked concentrations was between 90.7 and 98.4%, with relative standard deviations (n = 4) lower than 4.1%. Furthermore, the present approach was successfully applied to the quantitative determination of residues of benzoylurea insecticides in real samples.
Application of 3‐Dimensional Printing in Pediatric Living Donor Liver Transplantation: A Single‐Center Experience
Authors: Wang Pusen , Que Weitao , Zhang Mingman , Dai Xiaoke , Yu Kanru , Wang Chunguang , Peng Zhihai , Zhong Lin 
Published: February 2019

Three‐dimensional (3D) printing has been used to support organ transplantations. However, whether it helps remains unclear. This study aimed to present and assess the application of 3D‐printed liver models in pediatric living donor liver transplantation (LDLT). The 3D images were printed to touchable liver models with transparent liver parenchyma, specifically colored hepatic vessels, and biliary structures. A total of 30 consecutive recipients were enrolled in the study: 10 were operated on with the support of 3D printing (3D‐printing group) and 20 (control group) were operated on without it. Detailed photographs and data of the cases in the 3D‐printing group were presented. One patient underwent auxiliary partial orthotopic liver transplantation using the left lobe graft, in which the abdominal cavity model was also printed to test whether the planned graft fit the recipient’s abdominal cavity. The 3D‐printed models facilitated surgical planning and procedures, particularly in the management of hepatic veins and in the prevention of large‐for‐size syndrome. The operative time of donors in the 3D‐printing group was significantly shorter compared with the control group (2.3 ± 0.4 versus 3.0 ± 0.4 hours; P < 0.001). Inpatient costs for donors in the 3D‐printing group were 17.1% lower than those in the control group (34.6 ± 6.6 versus 41.7 ± 10.4 thousand ¥; P = 0.03). In conclusion, in small infants and complicated pediatric LDLT patients, 3D‐printed models can help minimize the risk of large‐for‐size syndrome and graft reduction. The 3D‐printed models may be conducive to liver graft procurement and intraoperative assistance in pediatric LDLT.
Translocation of Zymomonas mobilis pyruvate decarboxylase to periplasmic compartment for production of acetaldehyde outside the cytosol
Authors: Balodite Elina , Strazdina Inese , Martynova Jekaterina , Galinina Nina , Rutkis Reinis , Lasa Zane , Kalnenieks Uldis 
Published: February 2019

AbstractAcetaldehyde, a valuable commodity chemical, is a volatile inhibitory byproduct of aerobic fermentation in Zymomonas mobilis and in several other microorganisms. Attempting to improve acetaldehyde production by minimizing its contact with the cell interior and facilitating its removal from the culture, we engineered a Z. mobilis strain with acetaldehyde synthesis reaction localized in periplasm. For that, the pyruvate decarboxylase (PDC) was transferred from the cell interior to the periplasmic compartment. This was achieved by the construction of a Z. mobilis Zm6 PDC‐deficient mutant, fusion of PDC with the periplasmic signal sequence of Z. mobilis gluconolactonase, and the following expression of this fusion protein in the PDC‐deficient mutant. The obtained recombinant strain PeriAc, with most of its PDC localized in periplasm, showed a twofold higher acetaldehyde yield, than the parent strain, and will be used for further improvement by directed evolution.
Nuclear magnetic relaxation and diffusion study of the ionic liquids 1‐ethyl‐ and 1‐butyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide confined in porous glass
Authors: Ordikhani Seyedlar Amin , Stapf Siegfried , Mattea Carlos 
Published: February 2019

AbstractThe molecular dynamics of the room‐temperature ionic liquid 1‐butyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide (Bmim Tf2N) confined in porous glass is studied by nuclear magnetic resonance (NMR) relaxometry and diffusometry and is compared with the bulk dynamics over a wide temperature range. The molecular reorientation processes for anions and cations alike are found to be significantly affected by the presence of the glass interface at high temperatures. In this respect, the ionic liquid behaves similarly to polar liquids where proton NMR relaxation is governed by reorientations mediated by translational displacements (RMTDs). This process becomes less significant towards lower temperatures when the characteristic translational correlation times of the ions approach a timescale comparable with those of the RMTD process, and the relaxation dispersions in bulk and in confinement become similar below a temperature corresponding to about 1.2Tg, a value where the onset of dynamic heterogeneity has been observed before. The self‐diffusion coefficient, on the other hand, is found to be strongly reduced than the bulk within the accessible temperature range of 248 K and above and is significantly slower than expected from the tortuosity effect, suggesting that ion–surface interactions affect the macroscopic properties.
The Firefighter problem: Saving sets of vertices on cubic graphs
Authors: Duffy Christopher , MacGillivray Gary 
Published: February 2019

AbstractIn the context of the Firefighter problem, a deterministic model of the spread of a fire or virus on a graph, SFIRE is the decision problem that asks if a specified set of vertices can be prevented from burning. We show SFIRE remains NP‐complete even when restricted to graphs with maximum degree 3 even when the fire starts at a vertex of degree 2.
Intrasurgical Protein Layer on Titanium Arthroplasty Explants: From the Big Twelve to the Implant Proteome
Authors: Jäger Marcus , Jennissen Herbert P. , Haversath Marcel , Busch André , Grupp Thomas , Sowislok Andrea , Herten Monika 
Published: February 2019

PurposeAseptic loosening in total joint replacement due to insufficient osteointegration is an unsolved problem in orthopaedics. The purpose of the study is to obtain a picture of the initial protein adsorption layer on femoral endoprosthetic surfaces as the key to the initiation of osseointegration.Experimental designThe paper describes the first study of femoral stem explants from patients for proteome analysis of the primary protein layer. After 2 min in situ, the stems are explanted and frozen in liquid nitrogen. Proteins are eluted under reducing conditions and analyzed by LC‐MS/MS.ResultsAfter exclusion of proteins identified by a single peptide, the implant proteome is found to consist of 2802 unique proteins. Of these, 77% are of intracellular origin, 9% are derived from the plasma proteome, 8% from the bone proteome, and four proteins with highest specificity score could be assigned to the bone marrow proteome (transcriptome). The most abundant protein in the adsorbed total protein layer is hemoglobin (8–11%) followed by serum albumin (3.6–6%).ConclusionsA detailed knowledge of the initial protein film deposited onto the implants, as demonstrated here for the first time, may help to understand and predict the response of the osseous microenvironment to implant surfaces.
Commercial microwave link networks for rainfall observation: Assessment of the current status and future challenges
Authors: Chwala Christian , Kunstmann Harald 
Published: February 2019

Accurate observation of the high spatio‐temporal variability of rainfall is crucial for hydrometeorological applications. However, the existing observations from rain gauges and weather radars have individual shortcomings that can introduce considerable errors and uncertainties. A fairly new technique to get additional rainfall information is the usage of the country‐wide commercial microwave link (CML) networks for rainfall estimation by exploiting the measurements of rain‐induced attenuation along these CMLs. This technique has seen an increasing number of applications during the last years. Different methods have been developed to process the noisy raw data and to derive rainfall fields. It has been shown that CMLs can provide important line‐integrated rainfall information that complements pointwise rain gauge and spatial radar observations. There exist several limitations, though. Robustly dealing with the erratic fluctuations of the CML raw data is a challenge, in particular with the growing number of CMLs. How to correctly compensate for the biases from the effect of wet antenna attenuation for different CMLs also remains a crucial research question. Progress is additionally hampered by the lack of method intercomparisons, which in turn is hampered by restricted data sharing. Hence, collaboration is key for further advancements, also with regard to extended interaction with the CML network operators, which is a prerequisite to achieve increased data availability. In regions where rain gauges and weather radars are available, CMLs are a welcome complement. But in developing countries, which are characterized by weak technical infrastructure and which often suffer from water stress, additional rainfall information is a necessity. CMLs could play a crucial role in this respect.This article is categorized under:
Science of Water > Hydrological Processes
Science of Water > Water Extremes
Science of Water > Methods
Surveillance of antibiotic sensitivity pattern in chronic suppurative otitis media of an Indian teaching hospital
Authors: Chandra Sahu Mahesh , Swain Santosh Kumar 
Published: February 2019

IntroductionChronic suppurative otitis media (CSOM) is a common problem in worldwide and untreated CSOM leads to fatal complications like facial nerve paralysis, lateral sinus thrombosis, labyrinthitis, meningitis and brain abscess in developing country like India.ObjectiveTo isolate causative bacteria and antibiotic sensitivity pattern for CSOM and to know the prevalence of extended spectrum beta lactamases (ESBL) and Metallobetalactamases (MBL) in CSOM patients.MethodsA total of 500 ear swabs of clinical suspected CSOM patients were cultured on specific cultured medium and identified the bacteria with conventional methods. Then all the identified bacteria were subjected with specific antibiotics by the Kirby–Bauer's method to know the resistance pattern of antibiotics. ESBL and MBL strains were detected by double disc diffusion test.ResultsA total of 384 bacteria were isolated from 500 CSOM patients, among them 86 P. aeruginosa (22.40%), 112 Staphylococcus aureus (29.17%), 53 A. baumannii (13.80%), 32 E. aerogenes (18%), 26 C. freundii (6.77%), 24 K. oxytoca (6.25%), 23 P. vulgaris (5.99%), 18 K. pneumoniae (4.69%) and 10 P. mirabilis (2.60%) identified with conventional methods. From antibiotic disc diffusion methods 74.22% ESBL strains and 9.90% MBL strains were documented. Multidrug resistant strains of P. aeruginosa (86/384,22.40%) were more prevalent than those of S. aureus (112/384,29.17%) and other bacteria in ear discharges. Imipenem and vancomicin could control to gram negative bacteria and gram positive bacteria respectively.ConclusionContinuous and periodic evaluation of microbiological profile and antimicrobial sensitivity pattern of bacterial is essential for optimum management of CSOM patients.
SWAN/SOHO Lyman‐α Mapping: The Hydrogen Geocorona Extends Well Beyond the Moon
Authors: Baliukin I. I. , Bertaux J.‐L. , Quémerais E. , Izmodenov V. V. , Schmidt W. 
Published: February 2019

AbstractThe Earth's hydrogen exosphere Lyman‐α radiation was mapped with the Solar Wind Anisotropies/Solar and Heliospheric Observatory (SWAN/SOHO) instrument in January 1996, 1997, and 1998 (low solar activity). The use of a hydrogen absorption cell allowed to disentangle the interplanetary emission from the geocoronal one and to assign the absorbed signal almost entirely to the geocorona. The geocorona was found to extend at least up to 100 Earth radii (RE) with an intensity of 5 Rayleigh, an unprecedented distance well exceeding the recent results of Lyman Alpha Imaging Camera (LAICA) imager (∼50 RE), and encompassing the orbit of the Moon (∼60 RE). We developed a numerical kinetic model of the hydrogen atoms distribution in the exosphere, which includes the solar Lyman‐α radiation pressure and the ionization. The radiation pressure compresses the H exosphere on the dayside, producing a bulge of H density between 3 and 20 RE, which fits observed intensities very well. The SWAN Lyman‐α distribution of intensity was compared both to LAICA (2015) and to Orbiting Geophysical Observatory number 5 (1968) measurements. Integrated H densities of SWAN at a tangent distance of 7 RE are larger than LAICA/Orbiting Geophysical Observatory number 5 by factors 1.1–2.5, while we should expect a stronger effect of the radiation pressure at solar max. We discuss the possible role of H atoms in satellite orbits to explain this apparent contradiction. An onion‐peeling technique is used to retrieve hydrogen number density in the exosphere for the three SWAN observations. They show an excess of density versus models at large distances, which is likely due to nonthermal atoms (not in the model).
The Formation of Double‐Diffusive Layers in a Weakly Turbulent Environment
Authors: Shibley N. C. , Timmermans M.‐L. 
Published: February 2019

AbstractDouble‐diffusive stratification in the ocean is characterized by staircase structures consisting of mixed layers separated by high‐gradient interfaces in temperature and salinity. These double‐diffusive layers, which flux heat vertically, are observed over a vast region of the Arctic Ocean at the top boundary of the relatively warm and salty Atlantic water layer. In one formalism for the origin of double‐diffusive layers, staircase formation arises when a heat source is applied at the base of water that is stably stratified in salinity. This framework is extended to consider the effect of intermittent shear‐driven turbulence on diffusive‐convective staircase formation. One‐dimensional numerical model results indicate that there is a critical level of intermittent turbulence above which a staircase cannot form. This is framed in terms of a critical diffusivity ratio (ratio of effective salinity diffusivity to effective thermal diffusivity) that cannot be exceeded for a staircase to persist. This critical ratio is not a universal constant but rather differs for each staircase. Model results further indicate that layer thicknesses decrease with height in a staircase, with the variation in thickness over a staircase being more pronounced in the presence of intermittent turbulence. Finally, results suggest that increased diffusivity ratios lead to decreased heat fluxes across interfaces; if a staircase is subject to intermittent turbulence levels (below the critical level), vertical heat fluxes will be smaller than in the absence of shear‐driven turbulence. Findings are related to double‐diffusive staircases, and associated heat fluxes, in the weakly turbulent Arctic Ocean.
Structure, Transport, and Seasonality of the Atlantic Water Boundary Current North of Svalbard: Results From a Yearlong Mooring Array
Authors: Pérez‐Hernández M. Dolores , Pickart Robert S. , Torres Daniel J. , Bahr Frank , Sundfjord Arild , Ingvaldsen Randi , Renner Angelika H. H. , Beszczynska‐Möller Agnieska , von Appen Wilken‐Jon , Pavlov Vladimir 
Published: February 2019

AbstractThe characteristics and seasonality of the Svalbard branch of the Atlantic Water (AW) boundary current in the Eurasian Basin are investigated using data from a six‐mooring array deployed near 30°E between September 2012 and September 2013. The instrument coverage extended to 1,200‐m depth and approximately 50 km offshore of the shelf break, which laterally bracketed the flow. Averaged over the year, the transport of the current over this depth range was 3.96 ± 0.32 Sv (1 Sv = 106 m3/s). The transport within the AW layer was 2.08 ± 0.24 Sv. The current was typically subsurface intensified, and its dominant variability was associated with pulsing rather than meandering. From late summer to early winter the AW was warmest and saltiest, and its eastward transport was strongest (2.44 ± 0.12 Sv), while from midspring to midsummer the AW was coldest and freshest and its transport was weakest (1.10 ± 0.06 Sv). Deep mixed layers developed through the winter, extending to 400‐ to 500‐m depth in early spring until the pack ice encroached the area from the north shutting off the air‐sea buoyancy forcing. This vertical mixing modified a significant portion of the AW layer, suggesting that, as the ice cover continues to decrease in the southern Eurasian Basin, the AW will be more extensively transformed via local ventilation.
Flow Extremes as Spatiotemporal Control Points on River Solute Fluxes and Metabolism
Authors: Hensley Robert T. , Kirk Lily , Spangler Margaret , Gooseff Michael N. , Cohen Matthew J. 
Published: February 2019

AbstractFloods are dominant controls on export of solutes from catchments. In contrast, low‐flow periods such as droughts are potentially dominant control points for biogeochemical processing, enhancing spatiotemporal variation in solute concentrations, stream metabolism, and nutrient uptake. Using complementary time series (i.e., an Eulerian reference frame) and longitudinal profiling (i.e., a Lagrangian reference frame), we investigated hydrologic controls on temporal and spatial variation in solute flux and metabolism in the Lower Santa Fe River (FL, USA), where highly colored surface water mixes with exceptionally clear groundwater from springs. Gage measurements suggest groundwater inputs ranged from <1% (during extreme floods) to 86% (during extreme drought) of total discharge (Q). Mass transport of most solutes was dominated by high‐Q periods. Most solute C‐Q relationships exhibited statistically significant slope breakpoints near the transition between surface and groundwater dominance. In particular, parameters controlling water column light attenuation were chemostatic above median Q but markedly reduced at low Q. As a result, river metabolism and assimilatory nitrate (NO3−) uptake were consistently suppressed at high Q and enhanced at low Q, with greater variability in response to drivers other than water column light transmittance. Spatial variation in solute concentrations was also enhanced at low Q, induced by discrete groundwater inflow and biogeochemical processing along the reach. Contrasting reference frames yielded corroborative evidence for transport dominance at high Q, which damps spatiotemporal heterogeneity. In contrast, low‐Q periods enable localized mixing controls on solute concentrations and high rates of metabolism and nutrient processing that increase spatiotemporal variability.
Brazilian Scale of Hearing and Language Development: Normality Curve for Infants and Children from 0 to 24 Months Old with Normal Hearing
Authors: Moretti Claudia , Ribas Angela , Guarinello Ana , Rosa Marine , Riesemberg Renato , Vassoler Trissia , Sypczuk Giselle , Martins Jackeline 
Published: February 2019

Introduction Cochlear implants are currently the most effective technological resource to facilitate access to the hearing world for deaf people. Their use, especially when implanted early in children, reduces the impact of deafness on hearing as well as on the development of spoken language.
Objective To validate the first part of the Brazilian Scale of Hearing and Language Development (EDAL-1, in the Portuguese acronym) and to establish the normal curve in infants and children aged between 0 and 24 months old with normal hearing.
Method This is an experimental study of a descriptive nature, conducted with 92 infants and children with normal hearing. Every infant/child was evaluated audiologically, and the EDAL-1 was applied to their parents. The responses were categorized by applying the EDAL-1 every 3 months for each child.
Results The EDAL-1 was shown to be easily applied by the researcher and easily understood by the parents. It was possible to classify the sample every 3 months and describe the results. The average of the responses found in terms of scores for each age category shows an increasing scale following the evolution of the chronological age: 3 months—34.23 points; 6 months—54.68 points; 9 months—73 points; 12 months—82.5 points; 15 months—87 points; 18 months—91 points; 21 months—92.5 points, and 24 months—95.83 points.
Conclusion The normal curve for EDAL-1 was successfully established. The averages can be considered as the standard protocol for normality, serving as a reference for comparison with other populations.