bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of a human pluripotent stem cell‐derived model of neuronal development using multiplexed targeted proteomics
Authors: Dunkley Tom , Costa Veronica , Friedlein Arno , Lugert Sebastian , Aigner Stefan , Ebeling Martin , Miller Meghan T. , Patsch Christoph , Piraino Paolo , Cutler Paul , Jagasia Ravi 
Published: February 2015

PurposeHuman pluripotent stem cell (hPSC)‐derived cellular models have great potential to enable drug discovery and improve translation of preclinical insights to the clinic. We have developed a hPSC‐derived neural precursor cell model for studying early events in human brain development. We present protein‐level characterization of this model, using a multiplexed SRM approach, to establish reproducibility and physiological relevance; essential prerequisites for utilization of the neuronal development model in phenotypic screening‐based drug discovery.Experimental designProfiles of 246 proteins across three key stages of in vitro neuron differentiation were analyzed by SRM. Three independently hPSC‐derived isogenic neural stem cell (NSC) lines were analyzed across five to nine independent neuronal differentiations.ResultsOne hundred seventy‐five proteins were reliably quantified revealing a time‐dependent pattern of protein regulation that reflected protein dynamics during in vivo brain development and that was conserved across replicate differentiations and multiple cell lines.Conclusions and clinical relevanceSRM‐based protein profiling enabled establishment of the reproducibility and physiological relevance of the hPSC‐derived neuronal model. Combined with the successful quantification of proteins relevant to neurodevelopmental diseases, this validates the platform for use as a model to enable neuroscience drug discovery.
An interdomain boundary in RAG1 facilitates cooperative binding to RAG2 in formation of the V(D)J recombinase complex
Authors: Byrum Jennifer N. , Zhao Shuying , Rahman Negar S. , Gwyn Lori M. , Rodgers William , Rodgers Karla K. 
Published: February 2015

ABSTRACTV(D)J recombination assembles functional antigen receptor genes during lymphocyte development. Formation of the recombination complex containing the recombination activating proteins, RAG1 and RAG2, is essential for the site‐specific DNA cleavage steps in V(D)J recombination. However, little is known concerning how complex formation leads to a catalytically‐active complex. Here, we combined limited proteolysis and mass spectrometry methods to identify regions of RAG1 that are sequestered upon association with RAG2. These results show that RAG2 bridges an interdomain boundary in the catalytic region of RAG1. In a second approach, mutation of RAG1 residues within the interdomain boundary were tested for disruption of RAG1:RAG2 complex formation using fluorescence‐based pull down assays. The core RAG1 mutants demonstrated varying effects on complex formation with RAG2. Interestingly, two mutants showed opposing results for the ability to interact with core versus full length RAG2, indicating that the non‐core region of RAG2 participates in binding to core RAG1. Significantly, all of the RAG1 interdomain mutants demonstrated altered stoichiometries of the RAG complexes, with an increased number of RAG2 per RAG1 subunit compared to the wild type complex. Based on our results, we propose that interaction of RAG2 with RAG1 induces cooperative interactions of multiple binding sites, induced through conformational changes at the RAG1 interdomain boundary, and resulting in formation of the DNA cleavage active site.
Photonic crystal‐based fluid sensors: Toward practical application
Authors: Amrehn Sabrina , Wu Xia , Schumacher Christian , Wagner Thorsten 
Published: February 2015

We present an uncomplicated and inexpensive system for refractive index measurements of fluids based on the optical properties of photonic crystals (PhCs). The photonic band gap of inverse opals depends on the refractive index contrast between the crystal and the pore fluid. A change of refractive index of the pore fluid causes variations in the photonic band gap which can be observed as change in the wavelength of reflected light of the crystal (color change). Based on this principle a measurement cell for continuous fluid measurements was build (see figure) and used for identification of water/ethanol mixtures. Based on photonic band structure simulations general rules/recommendations for the design of this sensor type are given, for example, periodicity of the inverse opal, choice of material (refractive index), or measurement mode. For the proof of concept tungsten oxide (WO3) inverse opal structure was utilized as sensing layer. However, depending on the application other metal oxides or even polymers can be used. With the presented method a limit of detection (LoD) of 0.001 refractive index unit (RIU) was achieved.The figure shows the cross section of the custom built measurement cell: the reflectivity of the WO3 inverse opal (round image, left) is measured by a spectrometer in dependence of the fluid in contact to the crystal. Different refractive indices of the fluids cause spectral shifts of the reflection peak (right graph).
Evaluation of a combined glycomics and glycoproteomics approach for studying the major glycoproteins present in biofluids: Application to cerebrospinal fluid
Authors: Goyallon Arnaud , Cholet Sophie , Chapelle Manuel , Junot Christophe , Fenaille François 
Published: February 2015

RationaleGlycosylation is one of the most complex types of post‐translational modifications of proteins. The alteration of glycans bound to proteins from cerebrospinal fluid (CSF) in relation to disorders of the central nervous system is a highly relevant subject, but only few studies have focused on the glycosylation of CSF proteins.MethodsReproducible profiles of CSF N‐glycans were first obtained by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry after permethylation. Tryptic glycopeptides from CSF proteins were also enriched by hydrophilic interaction, and the resulting extracts divided into two equal aliquots. A first aliquot was enzymatically deglycosylated and analyzed by nano‐liquid chromatography/tandem mass spectrometry while the second one, containing intact enriched glycopeptides, was directly analyzed. Site‐specific data were obtained by combining the data from these three experiments.ResultsWe describe the development of a versatile approach for obtaining site‐specific information on the N‐glycosylation of CSF glycoproteins. Under these conditions, 124 N‐glycopeptides representing 55 N‐glycosites from 36 glycoproteins were tentatively identified. Special emphasis was placed on the analysis of glycoproteins/glycopeptides bearing 'brain‐type' N‐glycans, representing potential biologically relevant structures in the field of neurodegenerative disorders. Using our workflow, only a few proteins were shown to carry such particular glycan motifs.ConclusionsWe developed an approach combining N‐glycomics and N‐glycoproteomics and underline its usefulness to study the site‐specific glycosylation of major human CSF proteins. The final rather long‐term objective is to combine these data with those from other omics approaches to delve deeper into the understanding of particular neurological disorders. Copyright © 2015 John Wiley & Sons, Ltd.
Structural Dynamics of Pristine Headwater Streams from Southern Brazilian Amazon
Authors: Bleich M. E. , Mortati A. F. , André T. , Piedade M. T. F. 
Published: February 2015

AbstractAmazonian headwater streams trail a heterogeneous landscape, with marked natural variation of geomorphological conditions and hydrological periods. Southern Brazilian Amazon is subjected to high degradation pressure, mainly from deforestation. Hence, we characterize pristine headwaters structure (hydromorphology and water physical‐chemical variables) and variation among hydrological periods (dry, beginning of the rainy period and end of the rainy period), to define reference conditions for conservation‐oriented classification, monitoring and rehabilitation of the southern Brazilian Amazon streams. Stretches of 10 pristine streams from the Teles Pires River, a major tributary of the Tapajós River, were analysed for hydromorphology, water physical‐chemical variables and controlled for habitat integrity (forested proportion on buffer zones and habitat integrity index). We found variation among hydrological periods and spatial heterogeneity on pristine stream structure. Most variables showed great variation ranges at the same hydrological period and high variation coefficient values, reflecting the natural environmental heterogeneity among streams protected by a riparian forest. Variation among hydrological periods and spatial heterogeneity between streams in this region, combined with current high levels of deforestation, indicates the need for the conservation of a high proportion of streams and their respective riparian forests. Here, we have presented reference range values for monitoring and rehabilitation programs integrated in the Amazonian aquatic conservation efforts. Copyright © 2015 John Wiley & Sons, Ltd.
Solvothermal synthesis of nickel‐tungsten sulfides for 2‐propanol dehydration
Authors: Gómez‐Gutiérrez Claudia M. , Luque P. A. , Guerra‐Rivas G. , López‐Sánchez J. A. , Armenta M. A. , Quintana J. M. , Olivas A. 
Published: February 2015

SummaryThe bimetallic nickel‐tungsten catalysts were prepared via solvothermal method. The X‐ray Diffractometer (XRD) analysis revealed that the corresponding peaks at 14°, 34°, and 58° were for tungsten disulfide (WS2) hexagonal phase. The catalysts displayed different crystalline phase with nickel addition, and as an effect the WS2 surface area decreased from 74.7 to 2.0 m2g­−1. In this sense, high‐resolution transmission electron microscopy (HRTEM) showed the layers set in direction (002) with an onion‐like morphology, and in the center of the particles there is a large amount of nickel contained with 6–8 layers covering it. The catalytic dehydration of 2‐propanol was selective to propene in 100% at 250 °C for the sample with 0.7 of atomic ratio of Ni/Ni + W. SCANNING 37:165–171, 2015. © 2015 Wiley Periodicals, Inc.
Effect of alloy type on the life‐time of torsion‐preloaded nickel‐titanium endodontic instruments
Authors: Ha Jung‐Hong , Kim Sung Kyo , Cheung Gary Shun‐Pan , Jeong Seong Hwa , Bae Yong Chul , Kim Hyeon‐Cheol 
Published: February 2015

SummaryThis study was aimed to evaluate the effect of torsional preloads on the cyclic fatigue life of nickel‐titanium (NiTi) instruments with different history of heat treatments by manufacturers. WaveOne (Primary) made of M‐wire, K3XF (#30/0.06) of R‐phase, and ProTaper (F2) of conventional NiTi alloy was used. Each file was preloaded at four conditions (nil, 25, 50, and 75% of their mean ultimate torsional strength) before fatigue testing. The torsional preloads 10‐, 30‐, or 50‐times were applied by securing 5 mm of the file tip, rotating it until the preset torque was attained before returning to the origin. Then, the number of cycles to failure (NCF) was evaluated by rotational bending in a simulated canal. Data were analyzed using multiple linear regression analysis and two‐way ANOVA. Fractured instruments were examined under scanning electron microscope (SEM). SEM showed that most WaveOne after 75% preloading, regardless of repetitions, showed some longitudinal cracks parallel to the long axis of the file, which were rare for K3XF. Regression analysis revealed that the brand of instrument was the most critical factor. At up to 75% preloading, ProTaper and K3XF did not show any significant decline in NCF. For 30‐repetition groups of WaveOne, the 50 and 25% torsion preloaded groups showed a significantly higher NCF than the 0 and 75% groups. Within the limitations of this study, the alloy type of NiTi instrument have a significant effect on the phenomenon that a certain amount of torsional preload may improve the cyclic fatigue resistance of NiTi rotary instruments. SCANNING 37:172–178, 2015. © 2015 Wiley Periodicals, Inc.
Constructing authentication web in cloud computing
Authors: Zhao Gansen , Ba Zhongjie , Wang Xinming , Zhang Feng , Huang Changqin , Tang Yong 
Published: February 2015

AbstractCloud computing offers a cheap and efficient solution for the deployment of web applications. It results in a big increase of the number of service provider. Users hold multiple identities for using services from different domains. The openness of public clouds requires the authentication system to accept user identities from various domains and to support hybrid authentication protocols. This work proposes a cross‐domain single sign‐on mechanism to address the preceding issues and makes a formal mathematical model to analyze the security issues of the proposed mechanism's authentication architecture; furthermore, an algorithm is proposed to detect the authentication architecture's weak vertex whose failure would lead to a partial failure in the architecture. The proposed mechanism allows service providers to verify user identities in a decentralized way and allows users to unify their identities from various domains in a safe way. The verification process used in this mechanism is able to support hybrid authentication protocols as well as to accelerate the verification of credentials by eliminating single point of failure and single‐point bottleneck. Copyright © 2015 John Wiley & Sons, Ltd.
A new unpredictability‐based radio frequency identification forward privacy model and a provably secure construction
Authors: Yang Anjia , Liang Kaitai , Zhuang Yunhui , Wong Duncan S. , Jia Xiaohua 
Published: February 2015

AbstractThe privacy model of radio frequency identification (RFID) systems is for formalizing the adversarial capabilities and the security requirements of RFID anonymity and untraceability. Existing unpredictability‐based privacy models such as unp‐privacy, eunp‐privacy, unp*‐privacy, and unpτ‐privacy have captured different kinds of practical attacks, and some of them also have mutual authentication included. However, forward privacy, which allows a tag to remain untraceable even after its corruption, is yet to be well captured in any unpredictability‐based privacy models. In this paper, we describe some forward privacy‐related attacks that can be launched against RFID tags in practice. We then propose a new unpredictability‐based forward privacy model called unpfτ‐privacy. It extends an existing one called unpτ‐privacy, which has been shown to be stronger than ind‐privacy, unp‐privacy, and unp*‐privacy. We also propose an RFID protocol that supports forward privacy and mutual authentication. We show that it can be proven secure in the unpfτ‐privacy model. Copyright © 2015 John Wiley & Sons, Ltd.
Maternal subclinical vascular changes in fetal growth restriction with and without pre‐eclampsia
Authors: Stergiotou I. , Bijnens B. , Cruz‐Lemini M. , Figueras F. , Gratacos E. , Crispi F. 
Published: February 2015

ABSTRACTObjectiveTo assess maternal vascular structure and function in pregnancies complicated by fetal growth restriction (FGR), in women with and without pre‐eclampsia (PE) at the time of FGR diagnosis.MethodsWe evaluated 124 women with a pregnancy complicated by FGR, of whom 60 had PE and 64 did not, and compared these findings to those of 110 normal women (controls). The group of FGR pregnancies without PE was further subdivided according to gestational age at FGR diagnosis into early onset (< 32 weeks) or late onset (≥ 32 weeks). Maternal carotid intima–media thickness (IMT), blood pressure (BP), carotid artery distensibility (CD), circumferential wall stress (CWS) and inferior vena cava (IVC) collapsibility were assessed by ultrasound at the time of FGR diagnosis.ResultsCompared to controls, cases of FGR with PE showed increased maternal carotid IMT (0.425 (interquartile range (IQR), 0.381–0.486) vs 0.409 (IQR, 0.386–0.439) mm; P = 0.021), BP (mean, 109 (IQR, 101–117) vs 82  (IQR, 77–89) mmHg; P  < 0.001) and CWS (19.7 (IQR, 17.0–22.7) vs 12.2 (IQR, 11.1–13.7) kPa; P < 0.001), and reduced CD (25.3 (IQR, 15.7–35.6) vs 31.9 (IQR, 25.4–41.1) kPa−1 × 10−3; P = 0.037) and IVC collapsibility indices (0.07 (IQR, 0.06–1.11) vs 0.10 (IQR, 0.06–0.13); P  =  0.136). Similarly, compared to controls, in cases of FGR without PE maternal carotid IMT (0.436  (IQR, 0.392–0.476) mm; P  = 0.001) and BP (88 (IQR, 81–95) mmHg; P < 0.001) were increased but CD and IVC collapsibility were similar. When analysis was subclassified according to gestational age at diagnosis, IMT and CWS were significantly increased only in early‐onset FGR while BP was increased in both groups.ConclusionNormotensive women with pregnancy complicated by FGR share some subclinical vascular features with those of women with PE, which further reinforces the notion that, at least in a proportion of cases, there is a common placental disease that influences maternal cardiovascular features. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.
Prenatal features of isolated subependymal pseudocysts associated with adverse pregnancy outcome
Authors: Esteban H. , Blondiaux E. , Audureau E. , Sileo C. , Moutard M. L. , Gelot A. , Jouannic J. M. , Ducou le Pointe H. , Garel C. 
Published: February 2015

ABSTRACTObjectivesTo identify at prenatal ultrasound (US) the features of apparently isolated subependymal pseudocysts (SEPC) that may indicate underlying pathology and should lead to further investigations.MethodsThis was a retrospective study of cases with SEPC detected on prenatal US and/or magnetic resonance imaging (MRI). Those with apparently isolated SEPC at US were classified into two groups as follows: Group 1 (n = 29): normal prenatal US and MRI (except for SEPC) and normal outcome; Group 2 (n = 12): normal prenatal cerebral US (except for SEPC) and abnormal prenatal cerebral MRI with or without abnormal outcome. A third group (n = 9) included cases with abnormal prenatal US and MRI. The latter cases with obvious cerebral abnormalities at US were excluded from the statistical analysis as they do not represent a diagnostic dilemma for clinicians. Groups 1 and 2 were analyzed, comparing them with respect to their SEPC characteristics (size, number, location in relation to the caudothalamic notch and the ventricular horns and morphology) and extracerebral abnormalities.ResultsThe mean ± SD SEPC great axis was longer in Group 2 (11.67 ± 5.82 mm) than it was in Group 1 (8.00 ± 5.64 mm) (P = 0.021), suggesting an optimal cut‐off for size of SEPC of ≥ 9 mm (sensitivity = 75%, specificity = 62%) to maximize sensitivity for predicting pathological outcome. SEPC adjacent to the temporal horns and SEPC located posterior to the caudothalamic notch were observed more frequently in Group 2, indicating their association with poor outcome (P = 0.003 and P = 0.003, respectively). Atypical morphology and extracerebral abnormalities were observed more frequently in Group 2 (P = 0.013 and P = 0.044, respectively). There was no statistically significant difference between groups for either number or location of cysts along the inferior wall or adjacent to the lateral wall of the frontal horns (P = 0.591 and P = 0.156, respectively).ConclusionWhen apparently isolated SEPC are observed at prenatal US, further investigations should be performed under the following circumstances: (1) SEPC great axis ≥ 9 mm; (2) SEPC adjacent to the occipital and temporal horns; (3) SEPC located posterior to the caudothalamic notch; (4) SEPC with atypical morphology. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.
Syntheses and Structures of Two Novel Interdigitated Metal‐Quinolone Complexes: [Cu2(cfH)2(bptc)(H2O)]·4H2O and [Zn2(levofH)2(odpa)]·5.5H2O
Authors: Zhang Jin‐Ling , Yang Juan , Wang Xin , Zhang Hua‐Yi , Chi Xiao‐Lin , Chen Yu , Yang Qi , Xiao Dong‐Rong 
Published: February 2015

AbstractTwo novel interdigitated metal‐quinolone complexes, namely [Cu2(cfH)2(bptc)(H2O)]·4H2O (1) and [Zn2(levofH)2(odpa)]·5.5H2O (2) (bptc = 3,3′,4,4′‐benzophenonetetracarboxylate, cfH = ciprofloxacin, odpa = 4,4′‐oxydiphthalate, levofH = levofloxacin) were synthesized hydrothermally and characterized by elemental analyses, IR spectra, UV/Vis spectra, TG analyses, powder X‐ray diffraction, and single‐crystal X‐ray diffraction. Moreover, solid‐state photoluminescence property of compound 2 was also investigated at room temperature. Compound 1 exhibits a novel interdigitated architecture, which is built from 1D chains with side arms. The structure of compound 2 consists of 1D chains with dangling levofloxacin ligands protruding from both sides of the chain, and these chains are interdigitated with each other to generate a interdigitated framework.
Relations of Wolbachia Infection with Phylogeography of Philaenus spumarius (Hemiptera: Aphrophoridae) Populations Within and Beyond the Carpathian Contact Zone
Authors: Lis Agata , Maryańska-Nadachowska Anna , Kajtoch Łukasz 
Published: February 2015

Abstract

Wolbachia is the most widespread intracellular α-proteobacteria maternally inherited endosymbiont of insects and nematodes. These bacteria are associated with a number of different reproductive phenotypes of their hosts. Relatively few studies have dealt with distribution of infections across populations and with the influence of these bacteria on host genetic diversification and speciation. The aims of this study are to determine the distribution and rate of infection and to characterize the Wolbachia strains associated with Philaenus spumarius spittlebug (Hemiptera) by using multilocus sequencing typing (MLST) analysis and host phylogeography. The results showed that infection rate was significantly different between members of both main mitochondrial phylogenetic lineages of P. spumarius. We detected much higher infection rates of Wolbachia in P. spumarius populations from the north-east clade than the south-west clade. Moreover, the frequency of these infections varied within and outside the contact zone known from the Carpathians. Given the reproductive alterations which are often associated with this endosymbiont, Wolbachia probably maintain genetic differentiation of its hosts in its contact zone in the Carpathians. This is one of the first studies demonstrating the presence of Wolbachia across a large part of the range of insect species, including the contact zone. The spread of Wolbachia in P. spumarius populations can potentially cause speciation by compromising the potential reproductive barrier between infected and uninfected populations. We discuss possible implications of Wolbachia infection inducing cytoplasmic incompatibility in the population dynamics of this spittlebug but confirm that more studies are also required.
Unsteady dynamics of rapid perching manoeuvres
Authors: Polet Delyle T. , Rival David E. , Weymouth Gabriel D. 
Published: February 2015

AbstractA perching bird is able to rapidly decelerate while maintaining lift and control, but the underlying aerodynamic mechanism is poorly understood. In this work we perform a study on a simultaneously decelerating and pitching aerofoil section to increase our understanding of the unsteady aerodynamics of perching. We first explore the problem analytically, developing expressions for the added-mass and circulatory forces arising from boundary-layer separation on a flat-plate aerofoil. Next, we study the model problem through a detailed series of experiments at$\mathit{Re}=22\,000$and two-dimensional simulations at$\mathit{Re}=2000$. Simulated vorticity fields agree with particle image velocimetry measurements, showing the same wake features and vorticity magnitudes. Peak lift and drag forces during rapid perching are measured to be more than 10 times the quasi-steady values. The majority of these forces can be attributed to added-mass energy transfer between the fluid and aerofoil, and to energy lost to the fluid by flow separation at the leading and trailing edges. Thus, despite the large angles of attack and decreasing flow velocity, this simple pitch-up manoeuvre provides a means through which a perching bird can maintain high lift and drag simultaneously while slowing to a controlled stop.