bluuebunny/crossref_metadata_2025 huggingface dataset:
Reactivity of Planar‐Chiral α‐Ferrocenyl Carbocations towards Electron‐Rich Aromatics
Authors: Korb Marcus , Mahrholdt Julia , Liu Xianming , Lang Heinrich
Published: January 2019

The reaction of the enantiopure, planar‐chiral α‐ferrocenyl carbocation (Sp)‐2‐(P(=S)Ph2)FcCH2+ (Fc = Fe(η5‐C5H5)(η5‐C5H3)) towards electron‐rich arenes C6H5E (E = NH2, NMe2, NiPr2, NPh2, PPh2, P(=S)Ph2, OH, SH, SMe) regarding either a nucleophilic attack of the group E or an electrophilic aromatic substitution reaction of the arene at the CH2+ unit is reported. It was found that the amino, oxo or thio functionalities gave the respective ferrocenes in various product distributions, while the P‐based species didn't. Appropriate thiophosphine derivatives could be reduced to their PIII species that were applied as supporting ligands in atropselective C,C cross‐coupling reactions for the synthesis of sterically hindered biaryls, where sandwich compound (Sp)‐1‐(PPh2)‐2‐(o‐NMe2‐C6H4)CH2‐Fc gave an ee of 69 % (1 mol‐% [Pd]), which is up to date the highest observed value for planar‐chiral ferrocenes. The absolute configuration of the chiral ferrocenes was confirmed by single‐crystal X‐ray diffraction analysis. For seleno phosphane 1‐(P(=Se)Ph2)‐2‐(CH2OH)‐Fc a unique Se single‐atom transfer occurred within its reaction with Sanger's reagent. The presence of two chemically different Se atoms in 1‐(P(=Se)Ph2)‐2‐(((2,4‐(NO2)2‐C6H3)Se)CH2)‐Fc was confirmed by 77Se{1H} NMR spectroscopy and single‐crystal X‐ray diffraction analysis, respectively.
Nanocomposites of Polyoxometalates and Chitosan‐Based Polymers as Tuneable Anticancer Agents
Authors: Croce Matteo , Conti Simona , Maake Caroline , Patzke Greta R.
Published: January 2019

Invited for the cover of this issue is Greta Patzke from the University of Zurich, Switzerland. The cover image shows a cancer cell being attacked by polyoxometalate nanoparticles encapsulated with chitosan.
Stiffness measurement of nanosized liposomes using solid‐state nanopore sensor with automated recapturing platform
Authors: Lee Jung Soo , Saharia Jugal , Bandara Y. M. Nuwan D. Y. , Karawdeniya Buddini Iroshika , Goyal Gaurav , Darvish Armin , Wang Qingxiao , Kim Moon J. , Kim Min Jun
Published: January 2019

This paper describes a method to gauge the stiffness of nanosized liposomes – a nanoscale vesicle – using a custom‐made recapture platform coupled to a solid‐state nanopore sensor. The recapture platform electrically profiles a given liposome vesicle multiple times through automated reversal of the voltage polarity immediately following a translocation instance to re‐translocate the same analyte through the nanopore – provides better statistical insight at the molecular level by analyzing the same particle multiple times compared to conventional nanopore platforms. The capture frequency depends on the applied voltage with lower voltages (i.e., 100 mV) permitting higher recapture instances than at higher voltages (>200 mV) since the probability of particles exiting the nanopore capture radius increases with voltage. The shape deformation was inferred by comparing the normalized relative current blockade ( at the two voltage polarities to that of a rigid particle, i.e., polystyrene beads. We found that liposomes deform to adopt a prolate shape at higher voltages. This platform can be further applied to investigate the stiffness of other types of soft matters, e.g., virus, exosomes, endosomes, and accelerate the potential studies in pharmaceutics for increasing the drug packing and unpacking mechanism by controlling the stiffness of the drug vesicles.
A laboratory study of Equotip surface hardness measurements on a range of sandstones: What influences the values and what do they mean?
Authors: Desarnaud Julie , Kiriyama Kyoko , Bicer Simsir Beril , Wilhelm Katrin , Viles Heather
Published: January 2019

The Equotip rebound tester is a simple, non‐destructive technique to measure the surface hardness of materials. Having a low impact energy gives the Equotip advantages over the commonly used Schmidt Hammer on weathered rock and stone. In this study we have investigated the influence of different parameters (sample size, moisture content and surface roughness) on the surface hardness values obtained from freshly cut blocks of four types of sandstone. In a series of laboratory experiments both Single Impacts (SIM) and Repeat Impacts (RIM) methods have been used with C and D probes (which have different impact energies). Our results show that whilst sample size is of great importance we find that smaller samples can be reliably evaluated than previously reported. Moisture contents are also found to exert a more important influence on both SIM and RIM results than previously thought, with up to 26% lower hardness values recorded on saturated vs dry sandstone. Conversely, we find that surface roughness (over Sz values of 100 to 800 microns) does not have a significant impact on SIM measurements collected using the D probe. Both SIM and RIM data are found to be good proxies for compressive strength and open porosity, with SIM data collected with the C probe showing the best fits. Data collected using 3D microscopy helps visualize and quantify the small impact marks created by the Equotip and confirms that these are much reduced when using the C vs D probe. The results highlight the benefits of the Equotip to studies of the nature and deterioration of sandstone, the need for careful evaluation of any confounding factors which might influence the values obtained, and illustrate the different advantages of C and D probes. © 2019 John Wiley & Sons, Ltd.
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

This 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

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

Gliomas 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

Normal 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

The 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

Mesial 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

Objective

To investigate the effect of balloon occlusion of internal iliac arteries during cesarean hysterectomy in women with placenta previa accreta.

Methods

Retrospective 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.

Results

There 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.

Conclusion

Balloon 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

Antimicrobial 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

Glycogen 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

This 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

An 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.
MIF promotes perineural invasion through EMT in salivary adenoid cystic carcinoma
Authors: Zhang Mei , Li Zhu‐feng , Wang Hao‐fan , Wang Sha‐sha , Yu Xiang‐hua , Wu Jing‐biao , Pang Xin , Wu Jia‐shun , Yang Xiao , Tang Ya‐jie , Li Li , Liang Xin‐hua , Zheng Min , Tang Ya‐ling
Published: January 2019

Macrophage migration inhibitory factor (MIF) is a prominent orchestrator during the onset and progression of cancer. Recently, MIF was detected in salivary adenoid cystic carcinoma (SACC). However, its functional effect in perineural invasion (PNI) of SACC remained unknown. To illuminate the effect of MIF in genesis of PNI in SACC, we examined the expression of MIF, epithelial‐to‐mesenchymal transition (EMT)‐related markers, and Schwann cell markers by immunohistochemical analysis in 158 cases of SACC samples. Meanwhile, the correlation between MIF and PNI of SACC species was analyzed. Our data indicated that MIF expression was associated with PNI of SACC significantly. In vitro, the silence and overexpression experiments of MIF were performed in SACC cell lines. The ability of migration, invasion and PNI could be inhibited significantly by siRNA‐mediated MIF silence, and the occurrence of EMT and Schwann‐like cell differentiation was also inhibited by MIF silence in SACC‐LM cells. Overexpression of MIF in SACC‐83 cells using expressive plasmid showed the opposite effects. Our findings identified that an association between PNI and MIF expression existed. MIF may promote PNI of SACC by participating in cytoskeletal reorganization and pseudo foot formation induced by EMT and the Schwann‐like cell differentiation of SACC cells.
Resting‐state Functional MRI in Parkinsonian Syndromes
Authors: Filippi Massimo , Sarasso Elisabetta , Agosta Federica
Published: January 2019

Background

Functional 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.

Methods

This manuscript provides an educational review of the current use of resting‐state fMRI in the field of parkinsonian syndromes.

Results

Resting‐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.

Conclusions

There 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.
Gallic acid‐loaded electrospun cellulose acetate nanofibers as potential wound dressing materials
Authors: Wutticharoenmongkol Patcharaporn , Hannirojram Pornchita , Nuthong Pimchanok
Published: January 2019

Gallic acid (GA)–loaded cellulose acetate (CA) nanofiber mats with 10 to 40 wt.% GA contents (based on the weight of CA) were fabricated by electrospinning. The effects of GA contents and applied potential on the morphology and the average diameters of fibers were studied. The electrospun fiber mats containing 20 and 40 wt.% GA were investigated for their potential use as carrier of GA in wound dressing application. The GA‐loaded CA films were prepared by solvent casting technique for use in comparative studies. Determination of the release characteristics of GA from the GA‐loaded fiber mats and films was carried out by the total immersion and the transdermal diffusion through a pig skin method in acetate buffer solution (pH 5.5) or normal saline (pH 7.0) at either 32 or 37°C, respectively. In the total immersion method, the maximum amounts of the GA released from the fiber mats containing 20 and 40 wt.% GA in the acetate buffer were approximately 97% and 71% (based on the weight of initial GA), while those of the GA released into the normal saline were approximately 96% and 81%, respectively. Lower values were observed in the experiments of the transdermal diffusion through a pig skin method. The corresponding GA‐loaded CA films showed the lower amounts of GA released into media. The as‐loaded and the as‐released GA remained its antioxidant activity as investigated by 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) assay. Lastly, the GA‐loaded CA fiber mats exhibited antibacterial activity against Staphylococcus aureus, which showed the potential for use as wound dressing materials.
The effects of Nigella sativa on quality of life, disease activity index, and some of inflammatory and oxidative stress factors in patients with ulcerative colitis
Authors: Nikkhah‐Bodaghi Mehrnaz , Darabi Zahra , Agah Shahram , Hekmatdoost Azita
Published: January 2019

The aim of this study was to evaluate the effects of Nigella sativa (NS) supplementation in patients with ulcerative colitis. Two grams of NS powder or placebo were consumed for 6 weeks by 46 patients with active mild to moderate ulcerative colitis. Using valid and common questionnaires of colitis severity and blood sampling, we estimated disease activity index, quality of life, and some of inflammatory and oxidative stress factors at baseline and after 6 weeks of supplementation. NS‐elevated tumor necrosis factor‐alpha and high‐sensitivity‐c‐reactive‐protein as well as reduced malondialdehyde (p = 0.01, p = 0.02, and p = 0.005, respectively) compared with placebo. There was no significant difference between the two groups in serum total antioxidant capacity and nuclear factor kB levels. Total scores of Simple Clinical Colitis Activity Index Questionnaire and Inflammatory Bowel Disease Questionnaire‐9 were not different between the two groups; however, stool frequency score decreased significantly in NS group. Further clinical trials with different pattern of NS administration (the amount of total and divided daily doses, either powder type or standard extracts/oil and different time arrangement) are needed to clarify the vision.
Trailing edge subcomponent testing for wind turbine blades–Part A: Comparison of concepts
Authors: Rosemeier M. , Antoniou A. , Chen X. , Lahuerta F. , Berring P. , Branner K.
Published: January 2019

As a complement to the mandatory structural full‐scale test for wind turbine blades, the method of subcomponent testing has recently been proposed by international standards and guidelines for the experimental investigation of design‐critical full‐scale parts. This work investigated different subcomponent test (SCT) concepts for a trailing edge of an outboard segment from a 34‐m blade. Detailed analytical models to design the SCT concepts with regard to the boundary conditions were derived. Finite element analyses of the SCT's linear response were benchmarked against each other and against the full blade model in terms of displacements, rotations, in‐plane strains, and energy consumption. All SCT concepts were in good agreement with the full‐scale test with respect to the longitudinal strain response but showed deviations in the transverse and shear strain, as well as in the rotational and displacement response.
Sugar‐based biopolymers as novel imaging agents for molecular magnetic resonance imaging
Authors: Han Zheng , Liu Guanshu
Published: January 2019

Sugar‐based biopolymers have been recognized as attractive materials to develop macromolecule‐ and nanoparticle‐based cancer imaging and therapy. However, traditional biopolymer‐based imaging approaches rely on the use of synthetic or isotopic labeling, and because of it, clinical translation often is hindered. Recently, a novel magnetic resonance imaging (MRI) technology, chemical exchange saturation transfer (CEST), has emerged, which allows the exploitation of sugar‐based biopolymers as MRI agents by their hydroxyl protons‐rich nature. In the study, we reviewed recent studies on the topic of CEST MRI detection of sugar‐based biopolymers. The CEST MRI property of each biopolymer was briefly introduced, followed by the pre‐clinical and clinical applications. The findings of these preliminary studies imply the enormous potential of CEST detectable sugar‐based biopolymers in developing highly sensitive and translatable molecular imaging agents and constructing image‐guided biopolymer‐based drug delivery systems.

This article is categorized under:

Diagnostic Tools > in vivo Nanodiagnostics and Imaging

Therapeutic Approaches and Drug Discovery > Emerging Technologies
Topological gravity with non-compact matter
Authors: Li Songyuan , Troost Jan
Published: January 2019

Abstract

We couple twisted non-compact N = (2, 2) supersymmetric models to topological gravity in two dimensions. We propose expressions for the genus zero correlation functions based on a Kadomtsev-Petviashvili integrable hierarchy. Moreover, we prove recursion relations satisfied by the topological gravity amplitudes at all genera and compute characteristic critical exponents. We discuss the extent to which moving beyond the N = 2 central charge barrier opens a window on two-dimensional gravity with central charge larger than one.
Metabolic engineering of Corynebacterium glutamicum by synthetic small regulatory RNAs
Authors: Sun Dehu , Chen Jiuzhou , Wang Yu , Li Mingyue , Rao Deming , Guo Yanmei , Chen Ning , Zheng Ping , Sun Jibin , Ma Yanhe
Published: January 2019

Corynebacterium glutamicum is an important platform strain that is wildly used in industrial production of amino acids and various other biochemicals. However, due to good genomic stability, C. glutamicum is more difficult to engineer than genetically tractable hosts. Herein, a synthetic small regulatory RNA (sRNA)-based gene knockdown strategy was developed for C. glutamicum. The RNA chaperone Hfq from Escherichia coli and a rationally designed sRNA consisting of the E. coli MicC scaffold and a target binding site were proven to be indispensable for repressing green fluorescent protein expression in C. glutamicum. The synthetic sRNA system was applied to improve glutamate production through knockdown of pyk, ldhA, and odhA, resulting almost a threefold increase in glutamate titer and yield. Gene transcription and enzyme activity were down-regulated by up to 80%. The synthetic sRNA system developed holds promise to accelerate C. glutamicum metabolic engineering for producing valuable chemicals and fuels.
Fighting for the Soviet Union 2.0: Digital nostalgia and national belonging in the context of the Ukrainian crisis
Authors: Kozachenko Ivan
Published: January 2019

This paper focuses on the use of Soviet-era symbols, myths, and narratives within groups on VKontakte social media site over the initial stage of the Ukraine crisis (2014–2015). The study is based on qualitative content analysis of online discussions, visual materials, and entries by group administrators and commentators. It also applies link-analysis in order to see how groups on social media are interrelated and positioned online. It reveals that these online groups are driven primarily by neo-Soviet myths and hopes for a new version of the USSR to emerge. Over time, the main memory work in these groups shifted from Soviet nostalgia and “pragmatic” discourse to the use of re-constructed World War II memories in order to justify Russian aggression and to undermine national belonging in Ukraine. Reliance on the wartime mythology allowed for the labelling of Euromaidan supporters as “fascists” that should be eliminated “once again.” This powerful swirl of re-created Soviet memories allowed effective mobilization on the ground and further escalation of the conflict from street protests to the armed struggle.
Additive manufacturing continues composites market growth
Authors: Holmes Mark
Published: January 2019

Advances in machine technology and improvements in materials are progressing the use of additive manufacturing in the composites market – from prototypes to customized products. Reinforced Plastics reviews some recent developments.
An analytical model for asymmetric Mach reflection configuration in steady flows
Authors: Roy Shobhan , Gopalapillai Rajesh
Published: January 2019

An analytical model is presented for the configuration of Mach reflection (MR) due to the interaction of two-dimensional steady supersonic flow over asymmetric wedges. The present asymmetric MR model is an extension of an earlier model for the symmetric MR configuration. The overall Mach reflection (oMR) in the asymmetric wedge configuration is analysed as a combination of upper and lower half-domains of symmetric reflection configurations. Suitable assumptions are made to close the combined set of equations. The subsonic pocket downstream of the Mach stem is taken to be oriented along an average inclination, based on the streamline deflections by the Mach stem at the triple points. This assumption is found to give satisfactory results for all types of oMR configurations. The oMR configuration is predicted for all types of reflections such as direct Mach reflection (DiMR), stationary Mach reflection (StMR) and inverse Mach reflection (InMR). The reflection configuration and Mach stem shape given by the model for various sets of wedge angles, especially those giving rise to InMR, have been predicted and validated with the available numerical and experimental data. The von Neumann criterion for oMR is accurately predicted by this model. The asymmetric Mach stem profile is well captured. The variation of Mach stem height with wedge angle is also analysed and it is found that simplification of an asymmetric MR to a symmetric MR leads to over-prediction of the Mach stem height and hence the extent of the subsonic region.
Smithian platform-bearing gondolellid conodonts from Yiwagou Section, northwestern China and implications for their geographic distribution in the Early Triassic
Authors: Li Hanxiao , Jiang Haishui , Chen Yanlong , Wignall Paul B. , Wu Baojin , Zhang Zaitian , Zhang Muhui , Ouyang Zhumin , Lai Xulong
Published: January 2019

Abundant platform-bearing gondolellid conodonts, includingScythogondolella mosheri(Kozur and Mostler),Sc.phrynaOrchard and Zonneveld, andSc. cf.milleri(Müller), have been discovered from the Yiwagou Section of Tewo, together withNovispathodus waageni waageni(Sweet) andNv.w.eowaageniZhao and Orchard. This is the first report of Smithian platform-bearing gondolellids from the Paleo-Tethys region. In addition,Eurygnathodus costatusStaesche,E.hamadai(Koike),Parafurnishius xuanhanensisYang et al., and the generaPachycladinaStaesche,ParachirognathusClark, andHadrodontinaStaesche have also been recovered from Dienerian to Smithian strata at Yiwagou Section. Three conodont zones are established, in ascending order:Eurygnathodus costatus-E.hamadaiAssemblage Zone,Novispathodus waageni-Scythogondolella mosheriAssemblage Zone, and thePachycladina-ParachirognathusAssemblage Zone.

The platform-bearing gondolellids were globally distributed just after the end-Permian mass extinction, but the formerly abundantClarkinaKozur disappeared in the late Griesbachian. Platform-bearing gondolellids dramatically decreased to a minimum of diversity and extent in the Dienerian before recovering in the Smithian.ScythogondolellaKozur, probably a thermophilic and eurythermic genus, lived in all latitudes at this time whereas other genera did not cope with Smithian high temperatures and so became restricted to the high-latitude regions. However, the maximum temperature in the late Smithian likely caused the extinction of almost all platform-bearing gondolellids. Finally, the group returned to equatorial regions and achieved global distribution again in the cooler conditions of the late Spathian. We conclude that temperature (and to a lesser extent oxygen levels) exerted a strong control on the geographical distribution and evolution of platform-bearing gondolellids in the Early Triassic.
Fatou components and singularities of meromorphic functions
Authors: Barański Krzysztof , Fagella Núria , Jarque Xavier , Karpińska Bogusława
Published: January 2019

We prove several results concerning the relative position of points in the postsingular set P(f) of a meromorphic map f and the boundary of a Baker domain or the successive iterates of a wandering component. For Baker domains we answer a question of Mihaljević-Brandt and Rempe-Gillen. For wandering domains we show that if the iterates Un of such a domain have uniformly bounded diameter, then there exists a sequence of postsingular values pn such that ${\rm dist} (p_n, U_n)\to 0$ as $n\to \infty $. We also prove that if $U_n \cap P(f)=\emptyset $ and the postsingular set of f lies at a positive distance from the Julia set (in ℂ), then the sequence of iterates of any wandering domain must contain arbitrarily large disks. This allows to exclude the existence of wandering domains for some meromorphic maps with infinitely many poles and unbounded set of singular values.
A priori bounds and multiplicity of positive solutions for p-Laplacian Neumann problems with sub-critical growth
Authors: Boscaggin Alberto , Colasuonno Francesca , Noris Benedetta
Published: January 2019

Let 1 < p < +∞ and let Ω ⊂ ℝN be either a ball or an annulus. We continue the analysis started in [Boscaggin, Colasuonno, Noris, ESAIM Control Optim. Calc. Var. (2017)], concerning quasilinear Neumann problems of the type
$-\Delta _pu = f(u),\quad u > 0\,{\rm in }\,\Omega ,\quad \partial _\nu u = 0\,{\rm on }\,\partial \Omega .$We suppose that f(0) = f(1) = 0 and that f is negative between the two zeros and positive after. In case Ω is a ball, we also require that f grows less than the Sobolev-critical power at infinity. We prove a priori bounds of radial solutions, focussing in particular on solutions which start above 1. As an application, we use the shooting technique to get existence, multiplicity and oscillatory behaviour (around 1) of non-constant radial solutions.
Effect of the flavonoid hesperidin on glucose and fructose transport, sucrase activity and glycaemic response to orange juice in a crossover trial on healthy volunteers
Authors: Kerimi Asimina , Gauer Julia S. , Crabbe Susannah , Cheah Jia W. , Lau Jay , Walsh Rosa , Cancalon Paul F. , Williamson Gary
Published: January 2019

Although polyphenols inhibit glucose absorption and transportin vitro, it is uncertain whether this activity is sufficient to attenuate glycaemic responsein vivo. We examined this using orange juice, which contains high levels of hesperidin. We first used a combination ofin vitroassays to evaluate the potential effect of hesperidin and other orange juice components on intestinal sugar absorption and then tested whether this translated to an effect in healthy volunteers. Hesperidin attenuated transfer of14C-labelled glucose across differentiated Caco-2/TC7 cell monolayers. The involvement of the sugar transporter GLUT2 was demonstrated by experiments carried out in the absence of Na to exclude the contribution of sodium-glucose linked transporter 1 and further explored by the use ofXenopus laevisoocytes expressing human GLUT2 or GLUT5. Fructose transport was also affected by hesperidin partly by inhibition of GLUT5, while hesperidin, even at high concentration, did not inhibit rat intestinal sucrase activity. We conducted three separate crossover interventions, each on ten healthy volunteers using orange juice with different amounts of added hesperidin and water. The biggest difference in postprandial blood glucose between orange juice and control, containing equivalent amounts of glucose, fructose, sucrose, citric acid and ascorbate, was when the juice was diluted (ΔCmax=–0·5 mm,P=0·0146). The effect was less pronounced when the juice was given at regular strength. Our data indicate that hesperidin can modulate postprandial glycaemic response of orange juice by partial inhibition of intestinal GLUT, but this depends on sugar and hesperidin concentrations.