bluuebunny/crossref_metadata_2025_split huggingface dataset:
The impact of submersed aquatic vegetation on the development of river mouth bars
Authors: Lera Sara , Nardin William , Sanford Lawrence , Palinkas Cindy , Guercio Roberto 
Published: January 2019

AbstractThis work is inspired by the sudden resurgence of the submersed aquatic vegetation (SAV) bed in the Chesapeake Bay (USA). Because the SAV bed occurs at the mouth of the Bay's main tributary (Susquehanna River), it plays a significant role in modulating sediment and nutrient inputs from the Susquehanna to the Bay. Previous model studies on the impact of submersed aquatic vegetation on the development of river mouth bars lacked a complete mechanistic understanding. This study takes advantage of new advances in 3D computational models that include explicit physical‐sedimentological feedbacks to obtain this understanding. Specifically, we used Delft3D, a state‐of‐the‐art hydrodynamic model that provides fine‐scale computations of three‐dimensional flow velocity and bed shear stress, which can be linked to sediment deposition and erosion. Vegetation is modeled using a parameterization of hydraulic roughness that depends on vegetation height, stem density, diameter, and drag coefficient. We evaluate the hydrodynamics, bed shear stresses, and sediment dynamics for different vegetation scenarios under conditions of low and high river discharge. Model runs vary the vegetation height, density, river discharge, and suspended‐sediment concentration. Numerical results from the idealized model show that dense SAV on river mouth bars substantially diverts river discharge into adjacent channels and promotes sediment deposition at ridge margins, as well as upstream bar migration. Increasing vegetation height and density forms sandier bars closer to the river mouth and alteration of the bar shape. Thus, this study highlights the important role of SAV in shaping estuarine geomorphology, which is especially relevant for coastal management. © 2019 John Wiley & Sons, Ltd.
A 72-h exposure study with eastern oysters (Crassostrea virginica) and the nanomaterial graphene oxide
Authors: Khan Bushra , Adeleye Adeyemi S. , Burgess Robert M. , Smolowitz Roxanna , Russo Stephen M. , Ho Kay T. 
Published: January 2019

Abstract

Graphene is a 2-dimensional nanomaterial with unique mechanical, thermal, electrical, and optical properties. With increasing applications of graphene-family nanomaterials (GFNs) in electronics, biomedicine, and surface coatings, concern for their impacts on aquatic ecosystems is rising. Current information on the toxicity of GFNs, including graphene oxide, is scarce. Filter-feeding bivalves, such as eastern oysters, are good models for nanomaterial exposure studies. We present results from a 72-h static renewal oyster study using 1 and 10 mg/L graphene oxide, which, to our knowledge, is the first report on in vivo effects of graphene oxide exposures in marine bivalves. Water samples were analyzed for graphene oxide concentration and size assessments. Gill and digestive gland tissues were evaluated for lipid peroxidation and glutathione-S-transferase (GST) activity. In addition, gill sections were fixed for histopathological analyses. Elevated lipid peroxidation was noted in oysters exposed to 10 mg/L graphene oxide. No significant changes in GST activity were observed, but reduced total protein levels were found in digestive gland tissues of exposed oysters at both concentrations. Loss of mucous cells, hemocytic infiltration, and vacuolation were observed in gills of exposed oysters. The results indicate that short-term graphene oxide exposures can induce oxidative stress and epithelial inflammation and adversely affect overall oyster health. Further investigations regarding the fate and sublethal effects of graphene oxide are critical to understanding the risks associated with a rapidly growing graphene consumer market. Environ Toxicol Chem 2019;38:820–830. Published 2019 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.
Importance of GFAP isoform‐specific analyses in astrocytoma
Authors: van Bodegraven Emma J. , van Asperen Jessy V. , Robe Pierre A.J. , Hol Elly M. 
Published: January 2019

AbstractGliomas are a heterogenous group of malignant primary brain tumors that arise from glia cells or their progenitors and rely on accurate diagnosis for prognosis and treatment strategies. Although recent developments in the molecular biology of glioma have improved diagnosis, classical histological methods and biomarkers are still being used. The glial fibrillary acidic protein (GFAP) is a classical marker of astrocytoma, both in clinical and experimental settings. GFAP is used to determine glial differentiation, which is associated with a less malignant tumor. However, since GFAP is not only expressed by mature astrocytes but also by radial glia during development and neural stem cells in the adult brain, we hypothesized that GFAP expression in astrocytoma might not be a direct indication of glial differentiation and a less malignant phenotype. Therefore, we here review all existing literature from 1972 up to 2018 on GFAP expression in astrocytoma patient material to revisit GFAP as a marker of lower grade, more differentiated astrocytoma. We conclude that GFAP is heterogeneously expressed in astrocytoma, which most likely masks a consistent correlation of GFAP expression to astrocytoma malignancy grade. The GFAP positive cell population contains cells with differences in morphology, function, and differentiation state showing that GFAP is not merely a marker of less malignant and more differentiated astrocytoma. We suggest that discriminating between the GFAP isoforms GFAPδ and GFAPα will improve the accuracy of assessing the differentiation state of astrocytoma in clinical and experimental settings and will benefit glioma classification.
Generalizing age effects on brain structure and cognition: A two‐study comparison approach
Authors: Jockwitz Christiane , Mérillat Susan , Liem Franziskus , Oschwald Jessica , Amunts Katrin , Caspers Svenja , Jäncke Lutz 
Published: January 2019

AbstractNormal aging is accompanied by an interindividually variable decline in cognitive abilities and brain structure. This variability, in combination with methodical differences and differences in sample characteristics across studies, pose a major challenge for generalizability of results from different studies. Therefore, the current study aimed at cross‐validating age‐related differences in cognitive abilities and brain structure (measured using cortical thickness [CT]) in two large independent samples, each consisting of 228 healthy older adults aged between 65 and 85 years: the Longitudinal Healthy Aging Brain (LHAB) database (University of Zurich, Switzerland) and the 1000BRAINS (Research Centre Jülich, Germany). Participants from LHAB showed significantly higher education, physical well‐being, and cognitive abilities (processing speed, concept shifting, reasoning, semantic verbal fluency, and vocabulary). In contrast, CT values were larger for participants of 1000BRAINS. Though, both samples showed highly similar age‐related differences in both, cognitive abilities and CT. These effects were in accordance with functional aging theories, for example, posterior to anterior shift in aging as was shown for the default mode network. Thus, the current two‐study approach provides evidence that independently on heterogeneous metrics of brain structure or cognition across studies, age‐related effects on cognitive ability and brain structure can be generalized over different samples, assuming the same methodology is used.
Modular preprocessing pipelines can reintroduce artifacts into fMRI data
Authors: Lindquist Martin A. , Geuter Stephan , Wager Tor D. , Caffo Brian S. 
Published: January 2019

AbstractThe preprocessing pipelines typically used in both task and resting‐state functional magnetic resonance imaging (rs‐fMRI) analysis are modular in nature: They are composed of a number of separate filtering/regression steps, including removal of head motion covariates and band‐pass filtering, performed sequentially and in a flexible order. In this article, we illustrate the shortcomings of this approach, as we show how later preprocessing steps can reintroduce artifacts previously removed from the data in prior preprocessing steps. We show that each regression step is a geometric projection of data onto a subspace, and that performing a sequence of projections can move the data into subspaces no longer orthogonal to those previously removed, reintroducing signal related to nuisance covariates. Thus, linear filtering operations are not commutative, and the order in which the preprocessing steps are performed is critical. These issues can arise in practice when any combination of standard preprocessing steps including motion regression, scrubbing, component‐based correction, physiological correction, global signal regression, and temporal filtering are performed sequentially. In this work, we focus primarily on rs‐fMRI. We illustrate the problem both theoretically and empirically through application to a test–retest rs‐fMRI data set, and suggest remedies. These include (a) combining all steps into a single linear filter, or (b) sequential orthogonalization of covariates/linear filters performed in series.
Structural and functional asymmetry of medial temporal subregions in unilateral temporal lobe epilepsy: A 7T MRI study
Authors: Shah Preya , Bassett Danielle S. , Wisse Laura E.M. , Detre John A. , Stein Joel M. , Yushkevich Paul A. , Shinohara Russell T. , Elliott Mark A. , Das Sandhitsu R. , Davis Kathryn A. 
Published: January 2019

AbstractMesial temporal lobe epilepsy (TLE) is a common neurological disorder affecting the hippocampus and surrounding medial temporal lobe (MTL). Although prior studies have analyzed whole‐brain network distortions in TLE patients, the functional network architecture of the MTL at the subregion level has not been examined. In this study, we utilized high‐resolution 7T T2‐weighted magnetic resonance imaging (MRI) and resting‐state BOLD‐fMRI to characterize volumetric asymmetry and functional network asymmetry of MTL subregions in unilateral medically refractory TLE patients and healthy controls. We subdivided the TLE group into mesial temporal sclerosis patients (TLE‐MTS) and MRI‐negative nonlesional patients (TLE‐NL). Using an automated multi‐atlas segmentation pipeline, we delineated 10 MTL subregions per hemisphere for each subject. We found significantly different patterns of volumetric asymmetry between the two groups, with TLE‐MTS exhibiting volumetric asymmetry corresponding to decreased volumes ipsilaterally in all hippocampal subfields, and TLE‐NL exhibiting no significant volumetric asymmetries other than a mild decrease in whole‐hippocampal volume ipsilaterally. We also found significantly different patterns of functional network asymmetry in the CA1 subfield and whole hippocampus, with TLE‐NL patients exhibiting asymmetry corresponding to increased connectivity ipsilaterally and TLE‐MTS patients exhibiting asymmetry corresponding to decreased connectivity ipsilaterally. Our findings provide initial evidence that functional neuroimaging‐based network properties within the MTL can distinguish between TLE subtypes. High‐resolution MRI has potential to improve localization of underlying brain network disruptions in TLE patients who are candidates for surgical resection.
Internal iliac artery balloon occlusion during cesarean hysterectomy in women with placenta previa accreta
Authors: Chen Meng , Lv Bin , He Guolin , Liu Xinghui 
Published: January 2019

AbstractObjectiveTo investigate the effect of balloon occlusion of internal iliac arteries during cesarean hysterectomy in women with placenta previa accreta.MethodsRetrospective cohort study conducted using medical records of women with placenta previa and pathologically confirmed accreta taken from a single tertiary center in Chengdu, China, between January 1, 2012 and December 31, 2017. Baseline characteristics and pregnancy outcomes were compared between women with and without balloon occlusion of internal iliac arteries during cesarean delivery. The primary outcome was a composite outcome: estimated blood loss greater than or equal to 3.0 L, massive transfusion (transfusion of 10 or more units of packed red blood cells), and maternal intensive care unit admission.ResultsThere were 114 patients included in the study, 83 (72.8%) in the balloon group and 31 (27.2%) in the control group. Both propensity score analysis (18 [78.3%] vs 15 [65.2%], P=0.326) and multivariate logistic analysis (adjusted odds ratio 0.54, 95% confidence interval 0.20–1.45; P=0.221) showed that intraoperative balloon occlusion of internal iliac arteries was not associated with the primary outcome.ConclusionBalloon occlusion of internal iliac arteries during cesarean hysterectomy in women with placenta previa accreta was not associated with improved maternal outcomes.
Amphiphilic tetracationic porphyrins are exceptionally active antimicrobial photosensitizers: In vitro and in vivo studies with the free‐base and Pd‐chelate
Authors: Xuan Weijun , Huang Liyi , Wang Yuguang , Hu Xiaoqing , Szewczyk Grzegorz , Huang Ying‐Ying , El‐Hussein Ahmed , Bommer Jerry C. , Nelson Mark L. , Sarna Tadeusz , Hamblin Michael R. 
Published: January 2019

AbstractAntimicrobial photodynamic inactivation (aPDI) employs the combination of nontoxic photosensitizing dyes and visible light to kill pathogenic microorganisms regardless of drug‐resistance, and can be used to treat localized infections. A meso‐substituted tetra‐methylpyridinium porphyrin with one methyl group replaced by a C12 alkyl chain (FS111) and its Pd‐derivative (FS111‐Pd) were synthesized and tested as broad‐spectrum antimicrobial photosensitizers when excited by blue light (5 or 10 J/cm2). Both compounds showed unprecedented activity, with the superior FS111‐Pd giving 3 logs of killing at 1 nM, and eradication at 10 nM for Gram‐positive methicillin‐resistant Staphylococcus aureus. For the Gram‐negative Escherichia coli, both compounds produced eradication at 100 nM, while against the fungal yeast Candida albicans, both compounds produced eradication at 500 nM. Both compounds could be categorized as generators of singlet oxygen (ΦΔ = 0.62 for FS111 and 0.71 for FS111‐Pd). An in vivo study was carried out using a mouse model of localized infection in a partial thickness skin abrasion caused by bioluminescent Gram‐negative uropathogenic E. coli. Both compounds were effective in reducing bioluminescent signal in a dose‐dependent manner when excited by blue light (405 nm), but aPDI with FS111‐Pd was somewhat superior both during light and in preventing recurrence during the 6 days following PDT.
Does shuttling of glycogen‐derived lactate from astrocytes to neurons take place during neurotransmission and memory consolidation?
Authors: Dienel Gerald A. 
Published: January 2019

AbstractGlycogen levels in resting brain and its utilization rates during brain activation are high, but the functions fulfilled by glycogenolysis in living brain are poorly understood. Studies in cultured astrocytes have identified glycogen as the preferred fuel to provide ATP for Na+,K+‐ATPase for the uptake of extracellular K+ and for Ca2+‐ATPase to pump Ca2+ into the endoplasmic reticulum. Studies in astrocyte–neuron co‐cultures led to the suggestion that glycogen‐derived lactate is shuttled to neurons as oxidative fuel to support glutamatergic neurotransmission. Furthermore, both knockout of brain glycogen synthase and inhibition of glycogenolysis prior to a memory‐evoking event impair memory consolidation, and shuttling of glycogen‐derived lactate as neuronal fuel was postulated to be required for memory. However, lactate shuttling has not been measured in any of these studies, and procedures to inhibit glycogenolysis and neuronal lactate uptake are not specific. Testable alternative mechanisms to explain the observed findings are proposed: (i) disruption of K+ and Ca2+ homeostasis, (ii) release of gliotransmitters, (iii) imposition of an energy crisis on astrocytes and neurons by inhibition of mitochondrial pyruvate transport by compounds used to block neuronal monocarboxylic acid transporters, and (iv) inhibition of astrocytic filopodial movements that secondarily interfere with glutamate and K+ uptake from the synaptic cleft. Evidence that most pyruvate/lactate derived from glycogen is not oxidized and does not accumulate suggests predominant glycolytic metabolism of glycogen to support astrocytic energy demands. Sparing of blood‐borne glucose for use by neurons is a reasonable explanation for the requirement for glycogenolysis in neurotransmission and memory processing.
A natural and renewable biosorbent phase as a low‐cost approach in disposable pipette extraction technique for the determination of emerging contaminants in lake water samples
Authors: Morés Lucas , da Silva Ana Cristine , Merib Josias , Dias Adriana Neves , Carasek Eduardo 
Published: January 2019

AbstractThis study proposes an efficient analytical methodology using a biosorbent (cork) as an extraction phase in disposable pipette extraction technique for the rapid determination of the emerging contaminants methyl paraben, ethyl paraben, benzophenone, 3‐(4‐methylbenzylidene) camphor and 2‐(ethylhexyl)‐4‐(dimethylamino) benzoate in lake water samples using high‐performance liquid chromatography with diode array detection. The optimized conditions were comprised of 800 μL of sample, three cycles of 30 s each for the extraction, pH 6, addition of 30% w/v of NaCl. For the desorption step, the optimized desorption conditions were achieved with 100 μL of a mixture comprised of 50% methanol and 50% acetonitrile v/v, using one cycle of 30 s. Excellent analytical performance was achieved with limits of detection of 0.6 μg/L for methyl paraben to 1.4 μg/L for 3‐(4‐methylbenzylidene) camphor, and the limit of quantitation varied from 2 μg/L for methyl paraben to 4.3 μg/L 3‐(4‐methylbenzylidene) camphor, respectively. The correlation coefficients ranged from 0.9962 for ethyl paraben to 0.9980 for methyl paraben. The method accuracy varied from 71–132%, and the intraday precision ranged from 3 to 23% (n = 3) and interday from 9 to 23% (n = 9). The robustness was evaluated through Youden and Lenth's methods and indicated no significant variations in the results.
Application of characteristic fragment filtering with ultra high performance liquid chromatography coupled with high‐resolution mass spectrometry for comprehensive identification of components in Schisandrae chinensis Fructus
Authors: Yu Chanjuan , Xu Yang , Wang Meiling , Xie Ziye , Gao Xiaoyan 
Published: January 2019

AbstractAn integrated strategy of characteristic fragment filtering combined with target database screening based on ultra‐high‐performance liquid chromatography coupled with high‐resolution mass spectrometry was proposed for comprehensive profiling of components in Schisandrae chinensis Fructus. The strategy consisted of following five steps: (1) Representative standards were analyzed by ultra high performance liquid chromatography coupled with linear ion trap‐Orbitrap mass spectrometer for characteristic fragments and fragmentation rules of each structure type. (2) The raw data of 70% methanol extract was collected by ultra high performance liquid chromatography quadrupole time‐of‐flight tandem mass spectrometry. (3) The chemical components database that consisted of names, chemical formulas and structures of potential components in Schisandrae chinensis Fructus was established by summarizing previous literature to screen the collected liquid chromatography with mass spectrometry data and obtain matched compounds. (4) Characteristic fragments, literature, and reference standards were used to verify the matches. (5) Characteristic fragment filtering combined with online database querying was used to deduce potential new compounds. As a result, a total of 94 compounds were identified or characterized and 16 of them were potential new compounds. The study provided a reference for comprehensive characterization of ingredients in herbal medicine and formed the foundation for pharmacodynamic study of Schisandrae chinensis Fructus.
Resting‐state Functional MRI in Parkinsonian Syndromes
Authors: Filippi Massimo , Sarasso Elisabetta , Agosta Federica 
Published: January 2019

ABSTRACTBackgroundFunctional MRI (fMRI) has been widely used to study abnormal patterns of functional connectivity at rest in patients with movement disorders such as idiopathic Parkinson's disease (PD) and atypical parkinsonisms.MethodsThis manuscript provides an educational review of the current use of resting‐state fMRI in the field of parkinsonian syndromes.ResultsResting‐state fMRI studies have improved the current knowledge about the mechanisms underlying motor and non‐motor symptom development and progression in movement disorders. Even if its inclusion in clinical practice is still far away, resting‐state fMRI has the potential to be a promising biomarker for early disease detection and prediction. It may also aid in differential diagnosis and monitoring brain responses to therapeutic agents and neurorehabilitation strategies in different movement disorders.ConclusionsThere is urgent need to identify and validate prodromal biomarkers in PD patients, to perform further studies assessing both overlapping and disease‐specific fMRI abnormalities among parkinsonian syndromes, and to continue technical advances to fully realize the potential of fMRI as a tool to monitor the efficacy of chronic therapies.
Synergistic effect of cocondensed nanosilica in intumescent flame‐retardant polypropylene
Authors: Ding Siyin , Liu Peng , Gao Chong , Wang Feng , Ding Yanfen , Zhang Shimin , Yang Mingshu 
Published: January 2019

Amino‐functionalized nanosilica (SiO2‐NH2) was prepared through cocondensation method using aminopropyltriethoxysilane as comonomer to hydrolyze and cocondense with tetraethylorthosilicate. The synergistic effect of combination of ammonium polyphosphate and pentaerythritol with SiO2‐NH2 on the thermal and flame‐retardant properties of intumescent flame‐retardant (IFR) polypropylene (PP) has been investigated by thermogravimetric analysis (TGA), scanning electron microscopy, Raman spectra, X‐ray diffraction (XRD), limiting oxygen index (LOI), and UL 94 tests. When 1.0 wt.% SiO2‐NH2 was added, the LOI value of the PP/IFR composite with 25 wt.% of IFR increased from 26.6% to 31.7%, while the UL 94 rating raised from not classified to V‐0. The TGA data demonstrated that the SiO2‐NH2 nanoparticles increased the charred residue of the PP/IFR composites. The morphological structures and the orderliness of the charred residue proved that SiO2‐NH2 promoted the formation of compact intumescent charred layer, which effectively protected the underlying polymer from burning. The XRD patterns of the charred residue indicated that nanosilica reacted with APP to form SiP2O7 crystal structure during combustion, which was beneficial to the formation of compact charred layers. In comparison with the inorganic SiO2‐cal nanoparticles, the amino‐functionalized nanosilica revealed much more efficient synergistic flame‐retardant effect due to the difference of surface properties.