bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular control of gut formation in the spider Parasteatoda tepidariorum
Authors: Feitosa Natália Martins , Pechmann Matthias , Schwager Evelyn E. , Tobias‐Santos Vitória , McGregor Alistair P. , Damen Wim G. M. , Nunes da Fonseca Rodrigo 
Published: April 2017

AbstractThe development of a digestive system is an essential feature of bilaterians. Studies of the molecular control of gut formation in arthropods have been studied in detail in the fruit fly Drosophila melanogaster. However, little is known in other arthropods, especially in noninsect arthropods. To better understand the evolution of arthropod alimentary system, we investigate the molecular control of gut development in the spider Parasteatoda tepidariorum (Pt), the primary chelicerate model species for developmental studies. Orthologs of the ectodermal genes Pt‐wingless (Pt‐wg) and Pt‐hedgehog (Pt‐hh), of the endodermal genes, Pt‐serpent (Pt‐srp) and Pt‐hepatocyte‐nuclear factor‐4 (Pt‐hnf4) and of the mesodermal gene Pt‐twist (Pt‐twi) are expressed in the same germ layers during spider gut development as in D. melanogaster. Thus, our expression data suggest that the downstream molecular components involved in gut development in arthropods are conserved. However, Pt‐forkhead (Pt‐fkh) expression and function in spiders is considerably different from its D. melanogaster ortholog. Pt‐fkh is expressed before gastrulation in a cell population that gives rise to endodermal and mesodermal precursors, suggesting a possible role for this factor in specification of both germ layers. To test this hypothesis, we knocked down Pt‐fkh via RNA interference. Pt‐fkh RNAi embryos not only fail to develop a proper gut, but also lack the mesodermal Pt‐twi expressing cells. Thus, in spiders Pt‐fkh specifies endodermal and mesodermal germ layers. We discuss the implications of these findings for the evolution and development of gut formation in Ecdysozoans.
Terrestrial capture of prey by the reedfish, a model species for stem tetrapods
Authors: Van Wassenbergh Sam , Bonte Christoffel , Michel Krijn B. 
Published: April 2017

AbstractDue to morphological resemblance, polypterid fishes are used as extant analogues of Late Devonian lobe‐finned sarcopterygians to identify the features that allowed the evolution of a terrestrial lifestyle in early tetrapods. Previous studies using polypterids showed how terrestrial locomotion capacity can develop, and how air ventilation for breathing was possible in extinct tetrapodomorphs. Interestingly, one polypterid species, the reedfish Erpetoichthys calabaricus, has been noted being capable of capturing prey on land. We now identified the mechanism of terrestrial prey‐capture in reedfish. We showed that this species uses a lifted trunk and downward inclined head to capture ground‐based prey, remarkably similar to the mechanism described earlier for eel‐catfish. Reedfish similarly use the ground support and flexibility of their elongated body to realize the trunk elevation and dorsoventral flexion of the anterior trunk region, without a role for the pectoral fins. However, curving of the body to lift the trunk may not have been an option for the Devonian tetrapodomorphs as they are significantly less elongated than reedfish and eel‐catfish. This would imply that, in contrast to the eel‐like extant species, evolution of the capacity to capture prey on land in early tetrapods may be linked to the evolution of the pectoral system to lift the anterior part of the body.
Concentration and retention of chlorophyll around the extrafloral nectary of Mallotus japonicus
Authors: Yamawo Akira , Suzuki Nobuhiko 
Published: April 2017

AbstractPlants need to allocate some of their limited resources for defense against herbivores as well as for growth and reproduction. However, the priority of resource allocation within plants has not been investigated. We hypothesized that plants with extrafloral nectaries (EFNs) invest more chlorophyll around their EFNs—to support a high rate of carbon fixation there—than in other leaf parts of young leaves. Additionally, this chlorophyll may remain around EFNs rather than in the other leaf parts. We used Mallotus japonicus plants to investigate the chlorophyll content at leaf centers and edges and around EFNs at four stages of leaf development: middle‐expanded young leaves, fully expanded mature leaves, senior leaves, and leaves prior to abscission. These four stages of development were located at the third, fifth, eighth, and eleventh leaf positions from the apex, respectively. The results revealed that the chlorophyll content around the EFN side of the third‐position leaves was higher than that at the leaf center or edge. Although the chlorophyll content in the fifth‐position leaves did not differ between those at the leaf edge and around EFNs, the chlorophyll content around EFNs in the eighth‐position leaves was higher than that at the leaf centre and edge. The volume of EF nectar was positively correlated with the chlorophyll content around EFN during the leaf stage, but it was not correlated with the chlorophyll content in the leaf center and edge, except in fifth‐position leaves. These findings suggest that M. japonicus plants facilitate and maintain secretion of EF nectar in their young and old leaves, respectively, through the concentration and retention of chlorophyll around EFNs.
Unusual antioxidant effects in multiphase and complex systems
Authors: Kasaikina Olga T. , Krugovov Dmitriy A. , Mengele Elena A. 
Published: April 2017

In recent years, a number of studies have produced evidence that the multiphase and boundary effects in the systems containing surfactants, have to be taken into account for the development of innovative antioxidant technologies of lipid containing products. This report presents some unusual antioxidant effects, which occur only in multiphase complex systems due to the influence of surfactants (S). Hydroperoxides (LOOH), the primary oxidation products, form mixed micelles with surfactants (S) {nLOOH…mS}. In the case of cationic surfactants (S+), an accelerated hydroperoxide decomposition resulted in free radical generation occurs. Moderate magnetic field affects the free radical escape from mixed micelles {nLOOH…mS+} into bulk solution; it can result in inhibiting of lipid oxidation in micellar system. Nonionic S can inhibit the catalyzed lipid oxidation by solubilization of the hydrophilic catalyst and spatial separation of the catalyst and substrate. Anionic surfactants alkylsulfates and alkylphosphates are effective antioxidants for alkylaromatic hydrocarbons due to the catalytic heterolytic decomposition of hydroperoxides into carbonyl compound and phenol which scavenges peroxyl radicals.Practical applications: Some antioxidant effects caused by surfactants, which occur only in multiphase systems, are presented. Hydroperoxides (LOOH), the primary oxidation products, form mixed micelles with surfactants (S) {nLOOH…mS}; in the case of cationic surfactants (S+), accelerated hydroperoxide decomposition resulted in free radical generation occurs. So, the mixture of cationic surfactants with hydroperoxides can be used as free radical initiators at moderate temperatures; anionic surfactants (S−) inhibit such processes. Alkylsulfates and alkylphosphates are effective antioxidants for alkylaromatic hydrocarbons due to the catalytic heterolytic decomposition of the alkylaromatic hydroperoxides into phenol and carbonyl compound. Nonionic surfactants can inhibit the catalyzed oil oxidation by solubilization of the hydrophilic catalyst and spatial separation of the catalyst and substrate. Moderate magnetic field decreases the free radical escape from mixed micelles {nLOOH…mS+} into bulk solution; it can result in the inhibition of oil oxidation in the micellar system.External static magnetic field, SMF, 60–150 mT, reduces the yield of radicals in the decomposition of hydroperoxides in mixed micelles with cationic surfactants and acetylcholine chloride (ACh); by this reason SMF can retard lipid oxidation in the presence of ACh and cationic surfactants.
Viscosity based droplet size controlling in negative pressure driven droplets generator for large‐scale particle synthesis
Authors: Li Hanlin , Xue Yijun , Xu Meng , Zhao Wenfeng , Zong Chenghua , Liu Xiaojun , Zhang Qingquan 
Published: April 2017

The poor control and regulation of droplets limit the applications of negative pressure driven droplet generator (NPDDG). Here, we present a simple method to control droplet size in NPDDG via varying the oil viscosity. Depending on the infinite intersolubility of high viscous mineral oil and low viscous hexadecane, we obtain a series of oils with kinematic viscosities linearly varied from 4.2 to 194.6 mm2/s. By using these oils as continuous phases, monodisperse droplets are fabricated with controllable size in NPDDG. This viscosity‐based droplet regulation method is effective, reliable, and compatible with scale‐up processes. Compared with droplet generator driven by positive pressure, the presented method can fabricate hydrogel particles massively, without complicated multilayer chip structure and complex fluid controlling, which may extend the potential of NPDDG in droplets based high‐throughput assay or large‐scale materials synthesis.
Chiral analysis of α‐diimine Ru(II) and Fe(II) complexes by capillary electrophoresis using sulfated cyclodextrins as stereoselectors
Authors: Sázelová Petra , Koval Dušan , Severa Lukáš , Teplý Filip , Kašička Václav 
Published: April 2017

CE using randomly highly sulfated α‐, β‐, and γ‐CDs (S‐α‐CD, S‐β‐CD, S‐γ‐CD), sulfobutylether‐β‐CD (SBE‐β‐CD), single isomer (6‐O‐sulfo) α‐, β‐, and γ‐CDs, and their derivatives as stereoselectors was applied to chiral analysis of polypyridyl complexes of [Ru(bpy)3]2+, [Ru(phen)3]2+, and [Fe(phen)3]2+ (bpy = 2,2′‐bipyridine; phen = 1,10 phenanthroline). The best separations of Δ‐ and Λ‐enantiomers of the these complexes with high resolution (up to R1,2 = 7.0) and short analysis times (10–20 min) were achieved in the BGE composed of 22 mM NaOH/35 mM H3PO4, pH 2.4, containing 1.5–6.0 mM S‐α‐CD or S‐β‐CD, or SBE‐β‐CD as chiral selectors. The developed method was applied to the assessment of enantiomeric purity of several samples of [Ru(bpy)3]2+ catalyst. CE experiments were performed in a homemade analyzer equipped with bare or hydroxypropylcellulose‐coated fused‐silica capillaries (total/effective length 40/29 cm, id/od 50/375 μm) and an UV absorption detector operating at 206 nm. In addition to chiral analysis, apparent binding constants of the complexes of [Ru(bpy)3]2+, [Ru(phen)3]2+, and [Fe(phen)3]2+ enantiomers with five sulfated CDs (S‐α‐CD, S‐β‐CD, S‐γ‐CD, SBE‐β‐CD, and 16Me‐8S‐γ‐CD) were determined from the dependence of their effective electrophoretic mobilities on the concentration of the CDs in the BGE by nonlinear regression analysis. Calculated apparent binding constants of these complexes were found to be in the (1.10–4.66) × 103 L/mol range. Moreover, it was shown that at selected concentrations of some S‐CDs and suppressed or very low electroosmotic flow, the exceptional enantioseparations with infinite resolution could be achieved.
Accelerated carbonation by cement kiln dust in aqueous slurries: chemical and mineralogical investigation
Authors: Medas Daniela , Cappai Giovanna , De Giudici Giovanni , Piredda Martina , Podda Simona 
Published: April 2017

AbstractCement kiln dust accelerated carbonation in aqueous slurries at 25°C and 3 bar PCO2 was investigated by X‐ray diffraction analysis, solution chemistry, scanning electron microscopy, and energy dispersive spectroscopy to better understand chemical and mineralogical processes governing CO2 uptake. Dissolution of lime, portlandite, and ettringite occurs primarily in the carbonation process. These provide Ca2+ ions to react with CO32− ions leading to calcite bulk precipitation from solution. Concomitantly, the dissolution of Ca‐(Al)‐silicate grains takes place but it is limited by the formation of a Si‐rich and Ca‐depleted rim which appears onto the grain surfaces due to an initial hydration step. The Si‐rich decalcified rim hinders the diffusion of Ca2+ ions from the core of silicate grains to the bulk solution. The diffusion of Ca ions through the rim is then the rate limiting step for the carbonation of Ca‐(Al)‐silicate, that accounts for up to 4% of the carbonation potential. Achieved results elucidate the processes governing CO2 uptake by cement kiln dust, and are fundamental in the perspective of enhanced CO2 sequestration by cement kiln dust. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd.
Single‐subject independent component analysis‐based intensity normalization in non‐quantitative multi‐modal structural MRI
Authors: Papazoglou Sebastian , Würfel Jens , Paul Friedemann , Brandt Alexander U. , Scheel Michael 
Published: April 2017

AbstractNon‐quantitative MRI is prone to intersubject intensity variation rendering signal intensity level based analyses limited. Here, we propose a method that fuses non‐quantitative routine T1‐weighted (T1w), T2w, and T2w fluid‐saturated inversion recovery sequences using independent component analysis and validate it on age and sex matched healthy controls. The proposed method leads to consistent and independent components with a significantly reduced coefficient‐of‐variation across subjects, suggesting potential to serve as automatic intensity normalization and thus to enhance the power of intensity based statistical analyses. To exemplify this, we show that voxelwise statistical testing on single‐subject independent components reveals in particular a widespread sex difference in white matter, which was previously shown using, for example, diffusion tensor imaging but unobservable in the native MRI contrasts. In conclusion, our study shows that single‐subject independent component analysis can be applied to routine sequences, thereby enhancing comparability in‐between subjects. Unlike quantitative MRI, which requires specific sequences during acquisition, our method is applicable to existing MRI data. Hum Brain Mapp 38:3615–3622, 2017. © 2017 Wiley Periodicals, Inc.
Transition of the functional brain network related to increasing cognitive demands
Authors: Finc Karolina , Bonna Kamil , Lewandowska Monika , Wolak Tomasz , Nikadon Jan , Dreszer Joanna , Duch Włodzisław , Kühn Simone 
Published: April 2017

AbstractNetwork neuroscience provides tools that can easily be used to verify main assumptions of the global workspace theory (GWT), such as the existence of highly segregated information processing during effortless tasks performance, engagement of multiple distributed networks during effortful tasks and the critical role of long‐range connections in workspace formation. A number of studies support the assumptions of GWT by showing the reorganization of the whole‐brain functional network during cognitive task performance; however, the involvement of specific large scale networks in the formation of workspace is still not well‐understood. The aims of our study were: (1) to examine changes in the whole‐brain functional network under increased cognitive demands of working memory during ann‐back task, and their relationship with behavioral outcomes; and (2) to provide a comprehensive description of local changes that may be involved in the formation of the global workspace, using hub detection and network‐based statistic. Our results show that network modularity decreased with increasing cognitive demands, and this change allowed us to predict behavioral performance. The number of connector hubs increased, whereas the number of provincial hubs decreased when the task became more demanding. We also found that the default mode network (DMN) increased its connectivity to other networks while decreasing connectivity between its own regions. These results, apart from replicating previous findings, provide a valuable insight into the mechanisms of the formation of the global workspace, highlighting the role of the DMN in the processes of network integration.Hum Brain Mapp 38:3659–3674, 2017. ©2017 Wiley Periodicals, Inc.
Contributions of imprecision inPET‐MRIrigid registration to imprecision in amyloidPETSUVRmeasurements
Authors: Schwarz Christopher G. , Jones David T. , Gunter Jeffrey L. , Lowe Val J. , Vemuri Prashanthi , Senjem Matthew L. , Petersen Ronald C. , Knopman David S. , Jack Clifford R. ,   The Alzheimer's Disease Neuroimaging Initiative
Published: April 2017

AbstractQuantitative measurement of β‐amyloid from amyloid PET scans typically relies on localizing target and reference regions by image registration to MRI. In this work, we present a series of simulations where 50 small random perturbations of starting location and orientation were applied to each subject's PET scan, and rigid registration usingspm_coregwas performed between each perturbed PET scan and its corresponding MRI. We then measured variation in the output PET‐MRI registrations and how this variation affected the resulting SUVR measurements. We performed these experiments using scans of 1196 participants, half using 18F florbetapir and half using 11C PiB. From these experiments, we measured the magnitude of the imprecision in the rigid registration steps used to localize measurement regions, and how this contributes to the overall imprecision in SUVR measurements. Unexpectedly, we found for both tracers that the imprecision in these measurements depends on the degree of amyloid tracer uptake, and thus also indirectly on Alzheimer's disease clinical status. We then examined common choices of reference regions, and we show that SUVR measurements using supratentorial white matter references are relatively resistant to this source of error. We also show that the use of partial volume correction further magnifies the effects of registration imprecision on SUVR measurements. Together, these results suggest that this rigid registration step is an attractive target for future work in improving measurement techniques.Hum Brain Mapp 38:3323–3336, 2017. ©2017 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.
Characterization of decellularized ovine small intestine submucosal layer as extracellular matrix‐based scaffold for tissue engineering
Authors: Rashtbar Morteza , Hadjati Jamshid , Ai Jafar , Jahanzad Issa , Azami Mahmoud , Shirian Sadegh , Ebrahimi‐Barough Somayeh , Sadroddiny Esmaeil 
Published: April 2017

AbstractExtracellular matrix‐based scaffolds derived from mammalian tissues have been used in tissue engineering applications. Among all the tissues, decellularized small intestine submucosal layer (SIS) has been recently investigated for its exceptional characteristics and biocompatibilities. These investigations have been mainly focused on the decellularized porcine SIS; however, there has not been any report on ovine SIS (OSIS) layer. In this study, OSIS was decellularized and its physical, chemical, and morphological properties were evaluated. Decellularization was carried out using chemical reagents and various physical conditions. The effects of different conditions were evaluated on histological and biomechanical properties, quality of residual DNA, GAPDH gene expression, and biocompatibility. Results revealed satisfactory decellularization of OSIS which could be due to its thin thickness. Mechanical properties, structural form, and glycosaminoglycan contents were preserved in all the decellularized groups. In SDS‐treated groups, further cells and DNA residues were removed compared to the groups treated with Triton X‐100 only. No toxicity was observed in all treatments, and viability, expansion, and cell proliferation were supported. In conclusion, our results suggest that OSIS decellularized scaffold could be considered as an appropriate biological scaffold for tissue engineering applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 933–944, 2018.
Competence, Autonomy, and Relatedness as Motivators of Graduate Teaching Assistants
Authors: Kajfez Rachel L. , Matusovich Holly M. 
Published: April 2017

AbstractBackgroundGraduate teaching assistants (GTAs) play critical roles in undergraduate education. Past studies have examined various programs developed for GTAs, but little work exists that examines GTAs' personal experiences and perceptions in engineering education. To develop teaching environments and training programs that foster positive motivation in GTAs for teaching and improve the quality of their teaching, we need to better understand the factors that motivate them.PurposeSituated in self‐determination theory (SDT), the purpose of our study was to examine graduate students' motivation to teach by answering the research question, “What factors contribute to GTAs' competence, autonomy, and relatedness with regard to teaching?” We scoped the study broadly to include perceptions of events, occurrences, people, institutional structures, and demographics as potential factors.Design/MethodWe employed exploratory interview methods influenced by critical realism to understand GTAs' experiences. Our sample contained 12 participants from five different universities. We used a combination of a priori codes and open coding to determine the factors.ResultsWe identified five factors that affect the needs posited by SDT: training, previous experience, appointment structure, students, and teaching colleagues. Each factor uniquely contributed to a GTA's teaching motivation.ConclusionsGTAs are teachers, but they are also students. We recommend that faculty and administrators consider the five factors we identified and their unique individualized effects on GTAs as students and teachers when designing teaching experiences. This focus will lead to increased motivation in teaching and, with time, increases in the quality of teaching in engineering.
Identification of bioactive compounds in Shaoyao‐Gancao decoction using β2‐adrenoceptor affinity chromatography
Authors: Li Zehua , Gao Haiyang , Li Jiangying , Zhang Yajun 
Published: April 2017

Shaoyao‐Gancao decoction, a Chinese herbal formula, is composed of Paeoniae Radix alba and Glycyrrhiza Radix et rhizoma. It has been widely used to treat muscle spasms and asthma. However, little is known about the bioactive components of Shaoyao‐Gancao decoction. In the present study, the bioactive compounds in water‐extract of Shaoyao‐Gancao decoction were separated by the immobilized β2‐adrenoceptor affinity column and identified using quadrupole time‐of‐flight mass spectrometry. The affinity constants of the separated compounds that bind to β2‐adrenoceptor were determined by frontal analysis. Compound bioactivity was tested in a rat tracheal smooth muscle relaxation assay. We identified the bioactive compounds in the water extract of Shaoyao‐Gancao decoction that bound to the β2‐adrenoceptor as paeoniflorin and liquiritin. Paeoniflorin and liquiritin had only one binding site on the immobilized β2‐adrenoceptor, and the affinity constants were (2.16 ± 0.10) × 104 M−1 and (2.95 ± 0.15) × 104 M−1, respectively. Both compounds induced a concentration‐dependent relaxation of tracheal smooth muscle following K+‐stimulated contraction, and the relaxation effects were abrogated by the β2‐adrenoceptor antagonist, ICI 118551. Therefore, paeoniflorin and liquiritin are bioactive compounds in Shaoyao‐Gancao decoction and the β2‐adrenoceptor affinity chromatography is a useful tool for identifying potential β2‐adrenoceptor ligands in natural products used in traditional Chinese medicine.