bluuebunny/crossref_metadata_2025_split huggingface dataset:
Contrast‐enhanced computed tomography (CECT) attenuation is associated with stiffness of intact knee cartilage
Authors: Nickmanesh Reza , Stewart Rachel C. , Snyder Brian D. , Grinstaff Mark W. , Masri Bassam A. , Wilson David R. 
Published: July 2018

ABSTRACTContrast‐enhanced computed tomography (CECT) using charged contrast‐agents enables quantification of cartilage glycosaminoglycan content. Since glycosaminoglycan content is a key determinant of cartilage compressive stiffness, CECT measurements have the potential to non‐invasively assess cartilage stiffness. The objective of this study was to determine whether CECT attenuation, using a cationic contrast‐agent (CA4+), correlates with the stiffness of intact cartilage. Six fresh femoral and six fresh tibial compartments with intact cartilage were obtained from patients undergoing total knee replacement surgery. The instantaneous stiffness was determined for 25–50 points on the surface of each compartment using an established indentation technique. The samples were then immersed in CA4+ solution for 48 h, scanned in a micro‐CT scanner, and the average CECT attenuation at each indentation site was found for the superficial cartilage. A significant (p < 0.01) and positive correlation was observed between stiffness and CECT attenuation for sites from each individual cartilage surface, with correlation coefficients ranging from r = 0.37–0.57 and r = 0.48–0.69 (p < 0.01) for the tibia and femur, respectively. When data for each type of cartilage surface were pooled together, the correlation coefficients were r = 0.73 for femoral condyle data points and r = 0.49 for tibial plateau data points. CECT provided a map of cartilage stiffness across each surface, which allows regions of low stiffness to be identified. These findings support continued evaluation and development of quantitative imaging techniques to assess the functional properties of cartilage. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2641–2647, 2018.
Periodontal status of liver transplant candidates and healthy controls
Authors: Di Profio Bruna , Inoue Gislene , Marui Vanessa Costa , de França Bruno Nunes , Romito Giuseppe Alexandre , Ortega Karem Lopez , Holzhausen Marinella , Pannuti Claudio Mendes 
Published: July 2018

AbstractBackgroundThis study aimed to compare the periodontal status of liver transplant candidates (LTCs) with healthy controls.MethodsFifty liver transplant candidates (LTC group) and fifty patients without liver disease (control group) underwent a complete periodontal examination. The groups were matched according to sex, age, and smoking status. A structured questionnaire was applied to record demographic data, systemic health, and information related to liver disease. Full‐mouth complete periodontal examination of six sites per tooth was performed: gingival recession (GR), probing depth (PD), attachment loss (AL), bleeding on probing (BOP), and visible plaque index (VPI). The groups were compared in regard to periodontal clinical variables.ResultsPatients with cirrhosis had greater prevalence of periodontitis than healthy controls (P < 0.001). In addition, they had greater mean percentage of sites with AL ≥3 mm (P = 0.008) and AL ≥5 mm (P = 0.023), greater mean AL (P = 0.003), greater mean gingival recession (P < 0.001), and more missing teeth than in the control group (P = 0.02).ConclusionLiver transplant candidates presented greater prevalence, extent, and severity of periodontitis than matched control patients.
Influence of the bordering shelves on nutrient distribution in the Arctic halocline inferred from water column nitrate isotopes
Authors: Fripiat F. , Declercq M. , Sapart C. J. , Anderson L. G. , Bruechert V. , Deman F. , Fonseca‐Batista D. , Humborg C. , Roukaerts A. , Semiletov I. P. , Dehairs F. 
Published: July 2018

AbstractThe East Siberian Sea and contiguous western Arctic Ocean basin are characterized by a subsurface nutrient maximum in the halocline, generally attributed to both Pacific inflow and intensive remineralization in shelf bottom waters that are advected into the central basin. We report nitrogen and oxygen isotopic measurement of nitrate from the East Siberian Sea and western Eurasian Basin, in order to gain insight into how nitrate is processed by the microbial community and redistributed in the Arctic Ocean. A large decoupling between nitrate δ15N and δ18O is reported, increasing and decreasing upward from the Atlantic temperature maximum layer toward the surface, respectively. A correlation between water and nitrate δ18O indicates that most of the nitrate (> 60%) at the halocline has been regenerated within the Arctic Ocean. The increase in nitrate δ15N correlates with the fixed N deficit, indicating a causal link between the loss of fixed N and the 15N enrichment. This suggests that a significant share of benthic denitrification is driven by nitrate supplied by remineralization and partial nitrification, allowing residual 15N‐enriched ammonium to diffuse out of the sediments. By increasing nutrient concentrations and fixed N deficit in shelf bottom waters, this imprint is attenuated offshore following advection into the halocline by nitrate regeneration and mixing. Estimation of the sedimentary isotope effect related to benthic denitrification yields values in the range of 2.4–3.8‰, with its magnitude driven by both the degree of coupling between remineralization and nitrification, and fixed N concentrations in shelf bottom waters.
Factors affecting trophic compositions of offshore benthic invertebrates at a sub‐Antarctic archipelago
Authors: Puccinelli Eleonora , McQuaid Christopher D. , Ansorge Isabelle J. 
Published: July 2018

AbstractFood availability is a key regulator of the distribution, metabolism, and success of benthic populations. In deep sea ecosystems, hydrodynamics and depth play fundamental roles in determining benthic food resources. Recent studies suggest that the Southern Ocean sub‐Antarctic front is shifting southward, with implications for primary production and food availability around the sub‐Antarctic Islands embedded in the Antarctic Circumpolar Current. We used fatty acid (FA) and stable isotope (SI) analyses to investigate the trophic pattern of benthic invertebrates and suspended particulate matter (SPM) at three Depths (shallow: 100 m, middle: 300 m, and deep: 600 m) in three hydrographic regions with different flow and productivity regimes around the Prince Edward Islands. Both region and depth affected the SI values of SPM, while feeding guild was the key factor influencing consumer trophic values. Depth affected the δ15N of all trophic groups and the FA compositions of suspension feeders. Deeper samples had a higher δ15N and showed a greater proportion of mono‐ and saturated fatty acids, reflecting greater remineralization of SPM and of food reaching the seafloor. Region affected the δ13C and FA values of SPM, suspension feeders and deposit feeder/scavengers, with differences between the interisland and open ocean regions. This was probably linked to the retention of nutrients and phytoplankton between the islands. Critically, the effects of depth and hydrographic region were taxon specific, indicating that long‐term responses to environmental change may have complex consequences for the feeding ecology and viability of benthic populations, with implications for the higher trophic levels that these populations support.
Resolving the long‐standing puzzles about the observed Secchi depth relationships
Authors: Lee Zhongping , Shang Shaoling , Du Keping , Wei Jianwei 
Published: July 2018

AbstractVarious empirical relationships have been developed in the past nine decades to link the Secchi‐disk depth (ZSD) with the diffuse attenuation coefficient (KPAR), the euphotic zone depth (Zeu), and chlorophyll (Chl) concentration, where the latter two are important for the quantification and evaluation of photosynthesis in aquatic environments. There was also a classical theory regarding Secchi‐disk sighting, but large gaps existed between the observations and model outcomes. These gaps have puzzled the ocean community for > 60 yr and have resulted in contradictory conclusions regarding the interpretation and usefulness of ZSD. Here, we compare these measurements with data simulated based on an innovative theory and model regarding ZSD, and we found remarkable agreements between theoretical predictions and these century‐long observations. The results not only resolve the long‐standing puzzles associated with these observations, but also unify the relationships published in the literature. In particular, the ratio of Zeu to ZSD is found to be ∼ 3.5 for all waters, which is ∼ 45% greater than the consensus value of ∼ 2.4 suggested in the past for clear waters. In addition, the new model validates an empirical relationship between ZSD and Chl developed for global oceanic waters, thus providing strong support for using historical ZSD data to study changes of phytoplankton in global oceans in the past century.
Assimilation of ancient organic carbon by zooplankton in Tibetan Plateau lakes is depending on watershed characteristics
Authors: Su Y. , Hu E. , Liu Z. , Jeppesen E. , Middelburg J. J. 
Published: July 2018

AbstractAncient (i.e., radiocarbon depleted) organic carbon (OC) is exported from ice sheet, glacier, and permafrost systems and may be buried, respired, or assimilated in downstream aquatic systems. Few studies have explored the potential use of this ancient OC in lake food webs. We combined natural abundance radiocarbon and stable carbon isotope data (Δ14C andδ13C) to study ancient OC utilization by zooplankton in six lakes covering a large climate gradient on the central and peripheral Tibetan Plateau. A depleted Δ14C signature of dissolved and particulate OC was found in the inflowing streams and lakes, ranging from – 49‰ to – 569‰, corresponding to radiocarbon ages between 403 yr and 6757 yr. The Δ14C values for zooplankton in the lakes ranged from – 45‰ to – 264‰, reflecting that zooplankton obtain14C‐depleted signatures through assimilation of ancient OC and/or indirectly through consumption of phytoplankton or aquatic plant utilizing14C‐depleted inorganic carbon. Moreover, ancient OC from inflowing streams contributed more to zooplankton diets in the temperate glacier area than in the cold glacier area. Assimilation of ancient OC by zooplankton in lakes is not only affected by drainage basin characteristics, such as the recharge coefficient of the lake, but also by the biogeochemical properties of OC. Use of ancient OC by zooplankton in high‐altitude lakes may constitute an important link between the contemporary aquatic food webs and the glaciated watersheds. Our findings have important implications for the contribution of ancient carbon to the modern lake food webs of high‐altitude and polar lakes.
Combining nutrient, productivity, and landscape‐based regressions improves predictions of lake nutrients and provides insight into nutrient coupling at macroscales
Authors: Wagner Tyler , Schliep Erin M. 
Published: July 2018

AbstractEmpirical nutrient models that describe lake nutrient, productivity, and water clarity relationships among lakes play a prominent role in limnology. Landscape‐based regressions are also used to understand macroscale variability of lake nutrients, clarity, and productivity (hereafter referred to as nutrient‐productivity). Predictions from both models are used to inform eutrophication management globally. To date, these two classes of models are generally conducted separately, which ignores the known dependencies among nutrient‐productivity variables. We present a statistical model that integrates nutrient‐productivity and landscape‐based regressions—where lake nutrients, productivity, and clarity variables are modeled jointly. We fitted a joint nutrient‐productivity model to over 7000 lakes with three nutrients (total phosphorus, total nitrogen, nitrate concentrations), chlorophyllaconcentrations, and Secchi disk depth as response variables and landscape features as predictor variables. Because lakes in different regions respond to landscape features differently, we focused our analysis on two subregions with different dominant land uses, the agricultural Midwest and the forested Northeast U.S. Predictive performance was enhanced by modeling nutrient‐productivity variables jointly. We also found strong evidence that nutrient‐productivity variables were coupled, and that only nitrate may be decoupled from other nutrient‐productivity variables in the forested region. We speculate that these regional differences may be related to differences in the strength of biogeochemical cycles and stoichiometric controls between these regions. Jointly modeling nutrient‐productivity variables in lakes effectively integrates the two dominant approaches for studying lakes nutrient‐productivity relationships and provides novel insight into macroscale patterns of the coupling of nutrients, chlorophyll, and water clarity in lakes.
Photophysiology of nitrate limited phytoplankton communities in Kongsfjorden, Spitsbergen
Authors: Kulk Gemma , van de Poll Willem H. , Buma Anita G. J. 
Published: July 2018

AbstractIn Arctic coastal regions, the phytoplankton bloom is often initiated by meltwater induced stratification in spring, while subsequent nutrient depletion is believed to drive phytoplankton succession in summer. The associated changes in photophysiology are difficult to identify, because these can be governed by acclimation to light and nutrient availability as well as variations in phytoplankton biomass and taxonomic composition. In the present study, the consequences of nutrient limitation for photophysiology and growth were assessed in natural phytoplankton communities from Kongsfjorden, Spitsbergen. A series of nutrient addition experiments demonstrated N‐limitation from mid‐June onwards and possible co‐limitation with P later in summer. The onset of N‐limitation was associated with a pronounced change in taxonomic composition from a dictyochophytes to a haptophytes dominated community. Fast Repetition Rate fluorometry measurements of photosystem II (PSII) photophysiology showed that the dictyochophytes dominated community was characterized by high PSII efficiency and electron transport rates which were efficiently used for growth. Marked changes in PSII photophysiology were observed later in summer, with decreasing efficiencies, lower connectivity between reaction centers, and slower turnover rates. Simultaneously, alternative electron requirements downstream of PSII became more important and energy was likely allocated to the uptake of nutrients rather than carbon fixation and growth. Relief of nutrient limitation during the nutrient addition experiments did not lead to pronounced changes in PSII photophysiology. It is, therefore, concluded that PSII photophysiology of the phytoplankton community in Kongsfjorden is associated with changes in species composition rather than a direct effect of nutrient availability or nutrient limitation.
Near‐Field Characterization of Graphene Plasmons by Photo‐Induced Force Microscopy
Authors: Liu Jianxun , Park Sung , Nowak Derek , Tian Mengchuan , Wu Yanqing , Long Hua , Wang Kai , Wang Bing , Lu Peixiang 
Published: July 2018

AbstractThe near‐field features of graphene plasmons (GPs) using a recently developed photo‐induced force microscopy (PiFM) technique are characterized here. The GPs are excited by a mid‐infrared laser beam obliquely incident on graphene suspended over a metallic grating with a dielectric spacer. The PiFM records the optical force yielded by the interaction between the electric field of GPs in the normal direction and dipoles in a metallic tip. The magnitude of the optical force is proportional to the field intensity of the GPs. By detecting the interference pattern of GPs on the grating trenches, the wavelength and propagation distance of GPs can be obtained. The PiFM technique demonstrated here provides a powerful tool to precisely characterize GPs in a deeply subwavelength scale and aid in the design of nanoscale optical devices based on graphene.
Mixed EHL analysis of planetary drives with small teeth number difference considering real tooth geometry
Authors: Dai Ling , Pu Wei , Wang Jiaxu 
Published: July 2018

AbstractPlanetary drives with small teeth number difference are key components widely used for transmitting significant power. In general, these components are designed with short tooth depth to avoid the interference of addendum, which may have significant effect on contact conditions and lubrication characteristics. In the present study, a modified mixed elastohydrodynamic lubrication model is employed to analyse the lubrication performance in tooth pairs with consideration of real geometry profile (short tooth depth) and 3D machined roughness. Numerous sets of cases from meshing in to meshing out have been analysed under a wide range of operating conditions to study the tribological behaviour. Obtained results suggest that the lubrication and friction behaviours are much worse especially at meshing out points than those ignoring the influence of real tooth geometry. The modified elastohydrodynamic lubrication model is compared with finite element analysis results which indicate that it is able to handle practical cases in which the real contact width is much shorter than Hertzian contact width and can be employed for the analysis and design of planetary drives with small teeth number difference.
Tribocorrosion behaviour of F690 and 316L steel in artificial seawater
Authors: Ma Fuliang , Li Jinlong , Zeng Zhixiang , Gao Yimin 
Published: July 2018

AbstractIn this paper, the tribocorrosion behaviours of F690 steel and 316L steel in artificial seawater were studied for exploring the difference of tribocorroision behaviour between nonpassive materials and passive materials. The tribocorrosion tests reveal that the evolution of potential and current density of F690 steel under the simultaneous action of wear and corrosion is the opposite of that observed for 316L steel because of the different passivation capacities for the F690 and 316L steel. The passive materials possess a better tribocorrosion resistance than nonpassive materials in artificial seawater because of the presence of passive film based on the current research results. The wear resistance and corrosion resistance of F690 steel need to be further improved to extend the lifetime.
Protein‐protein interactions as antibiotic targets: A medicinal chemistry perspective
Authors: Cossar Peter J. , Lewis Peter J. , McCluskey Adam 
Published: July 2018

AbstractThere are 27 small molecule protein‐protein interaction (PPI) modulators in Phase I, II, and III clinical trials targeting cancer, viruses, autoimmune disorders, and as immune suppression agents. Targeting PPIs as an antibiotic drug discovery strategy remains in relative infancy by comparison. However, a number of molecules are in development which target PPI within the replisome, divisome, transcriptome, and translatome are showing significant promise at the medicinal chemistry stage of drug development. Hence, the success of future PPI agents as antibiotics will build upon the techniques and design strategies of these molecules.
Glycation of the Major Milk Allergen β‐Lactoglobulin Changes Its Allergenicity by Alterations in Cellular Uptake and Degradation
Authors: Perusko Marija , van Roest Manon , Stanic‐Vucinic Dragana , Simons Peter J. , Pieters Raymond H. H. , Cirkovic Velickovic Tanja , Smit Joost J. 
Published: July 2018

ScopeDuring food processing, the Maillard reaction (МR) may occur, resulting in the formation of glycated proteins. Glycated proteins are of particular importance in food allergies because glycation may influence interactions with the immune system. This study compared native and extensively glycated milk allergen β‐lactoglobulin (BLG), in their interactions with cells crucially involved in allergy.Methods and resultsBLG was glycated in MR and characterized. Native and glycated BLG were tested in experiments of epithelial transport, uptake and degradation by DCs, T‐cell cytokine responses, and basophil cell degranulation using ELISA and flow cytometry. Glycation of BLG induced partial unfolding and reduced its intestinal epithelial transfer over a Caco‐2 monolayer. Uptake of glycated BLG by bone marrow–derived dendritic cells (BMDC) was increased, although both BLG forms entered BMDC via the same mechanism, receptor‐mediated endocytosis. Once inside the BMDC, glycated BLG was degraded faster, which might have led to observed lower cytokine production in BMDC/CD4+ T‐cells coculture. Finally, glycated BLG was less efficient in induction of degranulation of BLG‐specific IgE sensitized basophil cells.ConclusionsThis study suggests that glycation of BLG by MR significantly alters its fate in processes involved in immunogenicity and allergenicity, pointing out the importance of food processing in food allergy.
Dynamic modelling of retrogressive landslides with emphasis on the role of clay sensitivity
Authors: Zhang Xue , Sloan Scott W. , Oñate Eugenio 
Published: July 2018

SummaryThis paper presents a detailed numerical study of the retrogressive failure of landslides in sensitive clays. The dynamic modelling of the landslides is carried out using a novel continuum approach, the particle finite element method, complemented with an elastoviscoplastic constitutive model. The multiwedge failure mode in the collapse is captured successfully, and the multiple retrogressive failures that have been widely observed in landslides in sensitive clays are reproduced with the failure mechanism, the kinematics, and the deposition being discussed in detail. Special attention has been paid to the role of the clay sensitivity on each retrogressive failure as well as on the final retrogression distance and the final run‐out distance via parametric studies. Moreover, the effects of the viscosity of sensitive clays on the failure are also investigated for different clay sensitivities.
Nonlinearly preconditioned L‐BFGS as an acceleration mechanism for alternating least squares with application to tensor decomposition
Authors: De Sterck Hans , Howse Alexander J.M. 
Published: July 2018

SummaryWe derive nonlinear acceleration methods based on the limited‐memory Broyden–Fletcher–Goldfarb–Shanno (L‐BFGS) update formula for accelerating iterative optimization methods of alternating least squares (ALS) type applied to canonical polyadic and Tucker tensor decompositions. Our approach starts from linear preconditioning ideas that use linear transformations encoded by matrix multiplications and extends these ideas to the case of genuinely nonlinear preconditioning, where the preconditioning operation involves fully nonlinear transformations. As such, the ALS‐type iterations are used as fully nonlinear preconditioners for L‐BFGS, or equivalently, L‐BFGS is used as a nonlinear accelerator for ALS. Numerical results show that the resulting methods perform much better than either stand‐alone L‐BFGS or stand‐alone ALS, offering substantial improvements in terms of time to solution and robustness over state‐of‐the‐art methods for large and noisy tensor problems, including previously described acceleration methods based on nonlinear conjugate gradients and the nonlinear generalized minimal residual method. Our approach provides a general L‐BFGS‐based acceleration mechanism for nonlinear optimization.