bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electron‐ and Hydride‐Reservoir Organometallics as Precursors of Catalytically Efficient Transition Metal Nanoparticles in Water
Authors: Fu Fangyu , Wang Qi , Ciganda Roberto , Martinez‐Villacorta Angel M. , Escobar Ane , Moya Sergio , Fouquet Eric , Ruiz Jaime , Astruc Didier 
Published: February 2018

AbstractNanoparticles (NPs) are actively investigated for their efficient use in catalysis, but their means of synthesis is a key factor influencing their catalytic properties owing to surface coverage with byproducts. Here, neutral electron‐ and hydride‐rich late transition metal organometallics are compared for the synthesis of late transition metal NPs in the presence of poly(vinylpirolidone) (PVP). In particular, the effect of electron‐reservoir donors, hydride‐reservoir donors, and electron‐rich dimers yielding NPs electrostatically stabilized by cationic organometallics are compared in terms of NP size and catalytic efficiency. The catalytic reactions scrutinized with excellent results include 4‐nitrophenol reduction to 4‐aminophenol by NaBH4 for the AuNPs and PdNPs, and Suzuki–Miyaura reactions for the PdNPs. The nature of the reductant has more influence on the NP size in the case of AuNPs than PdNPs, and the best NP catalysts are obtained with hydride‐reservoir complexes as reductants. The less bulky hydride donors are superior, with the complex [CoCp(ŋ4‐C5H6)] (Cp=ŋ5‐C5H5) giving the NPs with the best catalyst efficiencies for both reactions. Protection of the NP cores by the organometallic sandwich salt is found to be the key to catalytic efficiency.
Synthesis, Structure, and Magnetism of Tris(amide) [Ln{N(SiMe3)2}3]1− Complexes of the Non‐traditional +2 Lanthanide Ions
Authors: Ryan Austin J. , Darago Lucy E. , Balasubramani Sree Ganesh , Chen Guo P. , Ziller Joseph W. , Furche Filipp , Long Jeffrey R. , Evans William J. 
Published: February 2018

AbstractA new series of Ln2+ complexes has been synthesized that overturns two previous generalizations in rare‐earth metal reduction chemistry: that amide ligands do not form isolable complexes of the highly reducing non‐traditional Ln2+ ions, and that yttrium is a good model for the late lanthanides in these reductive reactions. Reduction of Ln(NR2)3 (R=SiMe3) complexes in THF under Ar with M=K or Rb in the presence of 2.2.2‐cryptand (crypt) forms crystallographically characterizable [M(crypt)][Ln(NR2)3] complexes not only for the traditional Tm2+ ion and the configurational crossover ions, Nd2+ and Dy2+, but also for the non‐traditional Gd2+, Tb2+, Ho2+, and Er2+ ions. Crystallographic data as well as UV/Vis, magnetic susceptibility, and density functional theory studies are consistent with the accessibility of 4fn5d1 configurations for Ln2+ ions in this tris(silylamide) ligand environment. The Dy2+ complex, [K(crypt)][Dy(NR2)3], has a higher magnetic moment than previously observed for any monometallic complex: 11.67 μB.
Enantioseparation of napropamide by supercritical fluid chromatography: Effects of the chromatographic conditions and separation mechanism
Authors: Zhao Lu , Xie Jingqian , Guo Fangjie , Liu Kai 
Published: February 2018

AbstractSupercritical fluid chromatography (SFC) is already used for enantioseparation in the pharmaceutical industry, but it is rarely used for the separation of chiral pesticides. Comparing with high performence liquid chromatography, SFC uses much more environmnetal friendly and economic mobile phase, supercritical CO2. In our work, the enantioseparation of an amide herbicide, napropamide, using three different polysaccharide‐type chiral stationary phases (CSPs) in SFC was investigated. By studying the effect of different CSPs, organic modifiers, temperature, back‐pressure regulator pressures, and flow rates for the enantioseparation of napropamide, we established a rapid and green method for enantioseparation that takes less than 2 minutes: The column was CEL2, the mobile phase was CO2 with 20% 2‐propanol, and the flow rate was 2.0 mL/min. We found that CEL2 demonstrated the strongest resolution capability. Acetonitrile was favored over alcoholic solvents when the CSP was amylose and 2‐propanol was the best choice when using cellulose. When the concentration of the modifiers or the flow rate was decreased, resolutions and analysis times increased concurrently. The temperature and back‐pressure regulator pressure exhibited only minor influences on the resolution and analysis time of the napropamide enantioseparations with these chiral columns. The molecular docking analysis provided a deeper insight into the interactions between the enantiomers and the CSPs at the atomic level and partly explained the reason for the different elution orders using the different chiral columns.
Automated negotiated user profiling across distributed social mobile clouds for resource optimisation
Authors: Benkhelifa Elhadj , Welsh Thomas , Tawalbeh Lo'ai , Jararweh Yaser 
Published: February 2018

SummaryWith mobile computing being the number one user paradigm of choice, and cloud computing becoming the chosen supporting infrastructure, the aggregation of these two areas is inevitable. Yet due to their novelty, they suffer from both inherited and new issues. Social computing theory can apply well to this fusion, such as pooling together in a social model to create ad hoc mobile clouds or by providing a greater functionality for mobile devices through resource augmentation from an external cloud. However, due to the highly contested resources within this setting, these resources must be negotiated within a social context. This paper argues that the application of social models to mobile cloud computing can allow mobile devices to employ cooperative strategies for resource sharing to allow aspects such as energy and costs to be minimised. Social computing is the means of using computing resources to augment human intelligence, mobiles can provide these enhancements to social intelligences but in a peer‐to‐peer manner. This paper proposes the design of a novel system which employs aggregated user and application resource profiling, in order to determine the most optimal place to process data, locally or on a remote cloud. Negotiation with the local cloud will then find a balance between optimum energy and resource utilisation.
Deep convolutional neural network for drowsy student state detection
Authors: Zhao Gang , Liu Shan , Wang Qi , Hu Tao , Chen Yawen , Lin Luyu , Zhao Dasheng 
Published: February 2018

SummaryDrowsy student state detection is helpful to understand the students' learning state, which is the necessary and basic aspect of teaching activities evaluation and assessment. The performance of traditional methods may deteriorate dramatically because of the external environment factors. In this paper, a novel drowsy student state detection method by integrating deep convolutional neural network is proposed at the first time in the literature. The proposed method avoids the complicated manual feature extraction operation and it can effectively reduce the interference of environmental factors in the application scenarios. Experimental results demonstrate that our approach can achieve high accuracy and lower error rate for drowsy student state detection. In addition, the results also show that our method outperforms traditional methods.
Unprecedented Ionization Processes in Mass Spectrometry Provide Missing Link between ESI and MALDI
Authors: Trimpin Sarah , Lee Chuping , Weidner Steffen M. , El‐Baba Tarick J. , Lutomski Corinne A. , Inutan Ellen D. , Foley Casey D. , Ni Chi‐Kung , McEwen Charles N. 
Published: February 2018

AbstractThe front cover artwork is provided by a multidisciplinary international group of physical/analytical scientists working in the general area of ionization for use in mass spectrometry. The image shows that key to multiply‐charged ion formation is the volatility of the matrix and, after successful transport of charged matrix:analyte clusters into the gas phase, desolvation as a secondary step. These results also suggest a connection between ESI and MALDI. Read the full text of the Article at 10.1002/cphc.201701246.
Controlling the Effective Oxygen Tension Experienced by Cells Using a Dynamic Culture Technique for Hematopoietic Ex Vivo Expansion
Authors: Tiwari Abhilasha , Wong Cynthia S. , Nekkanti Lakshmi P. , Deane James A. , McDonald Courtney , Li Jingang , Pham Yen , Sutherland Amy E. , Jenkin Graham , Kirkland Mark A. 
Published: February 2018

AbstractClinical hematopoietic stem/progenitor cell (HSPC) transplantation outcomes are strongly correlated with the number of cells infused. Hence, to generate sufficient HSPCs for transplantation, the best culture parameters for expansion are critical. It is generally assumed that the defined oxygen (O2) set for the incubator reflects the pericellular O2 to which cells are being exposed. Studies have shown that low O2 tension maintains an undifferentiated state, but the expansion rate may be constrained because of limited diffusion in a static culture system. A combination of low ambient O2 and dynamic culture conditions has been developed to increase the reconstituting capacity of human HSPCs. In this unit, the protocols for serum‐free expansion of HSPCs at 5% and 20% O2 in static and dynamic nutrient flow mode are described. Finally, the impact of O2 tension on HSPC expansion in vitro by flow cytometry and colony forming assays and in vivo through engraftment using a murine model is assessed. © 2018 by John Wiley & Sons, Inc.
Transglycosylation: A Key Reaction to Access Alkylpolyglycosides from Lignocellulosic Biomass
Authors: Jérôme François , Marinkovic Sinisa , Estrine Boris 
Published: February 2018

AbstractAn overview is provided on the recent advances in transglycosylation of cellulose and hemicellulose with either short‐chain or long‐chain alkyl alcohols. Catalytic processes are compared in terms of yield, selectivity and space‐time yield, with a view to identifying the most promising pathways for future developments. In this context, the synthesis of alkylpolyglycosides directly from lignocellulosic biomass is discussed while keeping in mind the impact of the botanical origin on the transglycosylation reaction and the product distribution. A section dedicated to the physicochemical properties and ecological footprint of alkylpolyglycosides is also included.
Identification of transcripts potentially involved in neural tube closure using RNA sequencing
Authors: Kindt Lexy M. , Coughlin Alicia R. , Perosino Tianna R. , Ersfeld Haley N. , Hampton Marshall , Liang Jennifer O. 
Published: February 2018

AbstractAnencephaly is a fatal human neural tube defect (NTD) in which the anterior neural tube remains open. Zebrafish embryos with reduced Nodal signaling display an open anterior neural tube phenotype that is analogous to anencephaly. Previous work from our laboratory suggests that Nodal signaling acts through induction of the head mesendoderm and mesoderm. Head mesendoderm/mesoderm then, through an unknown mechanism, promotes formation of the polarized neuroepithelium that is capable of undergoing the movements required for closure. We compared the transcriptome of embryos treated with a Nodal signaling inhibitor at sphere stage, which causes NTDs, to embryos treated at 30% epiboly, which does not cause NTDs. This screen identified over 3,000 transcripts with potential roles in anterior neurulation. Expression of several genes encoding components of tight and adherens junctions was significantly reduced, supporting the model that Nodal signaling regulates formation of the neuroepithelium. mRNAs involved in Wnt, FGF, and BMP signaling were also differentially expressed, suggesting these pathways might regulate anterior neurulation. In support of this, we found that pharmacological inhibition of FGF–receptor function causes an open anterior NTD as well as loss of mesodermal derivatives. This suggests that Nodal and FGF signaling both promote anterior neurulation through induction of head mesoderm.
A machine‐learning approach for extending classical wildlife resource selection analyses
Authors: Shoemaker Kevin T. , Heffelfinger Levi J. , Jackson Nathan J. , Blum Marcus E. , Wasley Tony , Stewart Kelley M. 
Published: February 2018

AbstractResource selection functions (RSFs) are tremendously valuable for ecologists and resource managers because they quantify spatial patterns in resource utilization by wildlife, thereby facilitating identification of critical habitat areas and characterizing specific habitat features that are selected or avoided.RSFs discriminate between known‐use resource units (e.g., telemetry locations) and available (or randomly selected) resource units based on an array of environmental features, and in their standard form are performed using logistic regression. As generalized linear models, standardRSFs have some notable limitations, such as difficulties in accommodating nonlinear (e.g., humped or threshold) relationships and complex interactions. Increasingly, ecologists are using flexible machine‐learning methods (e.g., random forests, neural networks) to overcome these limitations. Herein, we investigate the seasonal resource selection patterns of mule deer (Odocoileus hemionus) by comparing a logistic regression framework with random forest (RF), a popular machine‐learning algorithm. Random forest (RF) models detected nonlinear relationships (e.g., optimal ranges for slope and elevation) and complex interactions which would have been very challenging to discover and characterize using standard model‐based approaches. Compared with standardRSFmodels,RFmodels exhibited improved predictive skill, provided novel insights about resource selection patterns of mule deer, and, when projected across a relevant geographic space, manifested notable differences in predicted habitat suitability. We recommend that wildlife researchers harness the strengths of machine‐learning tools likeRFin addition to “classical” tools (e.g., mixed‐effects logistic regression) for evaluating resource selection, especially in cases where extensive telemetry data sets are available.
Electrochemistry of Azurin H117G in Complex with Molecular Wires on Edge Plane Pyrolytic Graphite Electrodes
Authors: Stan Razvan C. , Appel Jeroen , Sanghamitra Nusrat J.M. 
Published: February 2018

AbstractAzurin H117G has an engineered cavity that allows for a series of pyridine containing ligands to form a coordination complex with the protein redox center. The assembly, interfacial electron transfer rate and coverage on carbon electrodes of this azurin mutant in complex with a series of molecular wires have been determined. The determining role of favorable coupling to electrodes in obtaining enhanced electrical conductivity has been measured.
Understanding the Factors Affecting the Analytical Performance of Sandwich‐hybridization Genosensors on Gold Electrodes
Authors: Miranda‐Castro Rebeca , Santos‐Álvarez Noemí de‐los‐ , Lobo‐Castañón María Jesús 
Published: February 2018

AbstractHybridization‐based electrochemical DNA sensors have become a methodological mainstay in a wide variety of fields. Among the possible assay formats, sandwich hybridization is the most powerful one. It is so called because the target sequence to be measured is hybridized between two complementary sequences. The analytical performance of this class of sensors is influenced by many construction and operational parameters, which need to be optimized. In this work, we comparatively analyze the analytical performance of different sandwich hybridization sensors, constructed on gold surfaces modified by chemisorption. We find that the structures of the designed probes as well as the topography of the gold support and the nature of the monolayer are key parameters affecting the sensitivity and reproducibility of the genosensors. Other important operational parameters are also described. The results of this study could serve as a guide in the design of genosensors for future applications.
The Experts Weigh in: High‐Achieving, Low‐Income Students Reflect on Their Experience in and the Impact of a College Access Program
Authors: Millett Catherine M. , Kevelson Marisol J. C. 
Published: February 2018

AbstractAn evaluation of the Princeton University Preparatory Program (PUPP), a college access program for low‐income, high‐achieving public high school students, yielded favorable findings regarding the perceptions of program participants. Survey results, which include responses from all 71 participants in the 2015–2016 program, indicated that the participants perceived the program as positively impacting their academic and social–emotional skills, increasing their knowledge of the college application process, broadening their pool of target colleges, and exposing them to new arts and cultural experiences, as the program is intended to do. Scholars' responses also highlight the strength of the PUPP community and social network and confirm that PUPP is helping some scholars to address personal and financial challenges that could prevent them from participating in educational experiences such as PUPP. Findings also highlight the PUPP academic enrichment program as a possible area for growth.
Geochemistry and a metallogenic model for Nb–Ta‐bearing granitic pegmatites from the northern Qaidam Basin
Authors: Shao Tiequan , Jiang Kaituo , Liu Yunhuan , Tang Hanhua , Qin Jiachen , Hu Bo , Wang Qi , Zhang Yanan , Zhang Hu 
Published: February 2018

The Palaeoproterozoic Dakendaba Group and the Cambrian–Ordovician Tanjianshan Group occur on the northern margin of the Qaidam Basin. Their fracture structure is well developed, and intermediate‐acid rocks are widely distributed, providing an ideal setting for pegmatite mineralization. Field investigation has identified 200 pegmatite veins, of which more than 40 have various degrees of Nb and Ta mineralization. These pegmatites can be classified into four types, based on distribution, mineral assemblages, and a genesis sequence of ① microcline, ② microcline–albite, ③ albite, and ④ muscovite–albite. Pegmatite types ③ and ④ are typically mineralized, with Nb and Ta occurring as niobite and columbite–tantalite. These pegmatites have high silica and alkali content and are Al‐rich. The aluminium saturation index (A/CNK) is 1.36–1.60, and (A/NK) is 1.45–1.93. Their ∑REE values are 2.61–23.95 × 10−6. Other REE ratios have values of (La/Yb)N = 2.02–8.04, (La/Sm)N = 0.47–3.20, and (Gd/Yb)N = 1.34–4.93. Their REE distribution pattern is right‐inclined, with slight LREE enrichment. Negative Eu anomalies are apparent in types ① and ④ but not in types ② and ③. High field strength elements, such as Nb, Ta, Zr, and Hf, have low contents, with Y depletion. Concentrations of REE are generally low, although Sr and Ba are slightly enriched. Thus, pegmatites of this area have low Ca, K, and Al but high Na and Si and are rich in rare metal elements and poor in REEs. This suggests liquid immiscibility was involved in their metallogenic evolution process.
Garnet zoning in kyanite‐bearing eclogite from Golfo Aranci: New data on the early prograde P–T evolution in NE Sardinia, Italy
Authors: Cruciani Gabriele , Franceschelli Marcello , Scodina Massimo , Puxeddu Mariano 
Published: February 2018

Kyanite‐bearing eclogites from the Migmatite Complex of Golfo Aranci area, NE Sardinia, have been investigated using microstructural analyses and thermodynamic modelling in order to define their early metamorphic evolution and P–T path. The eclogites underwent a clockwise P–T path recorded by the different composition of garnet core, mantle, and rim. P–T pseudosection modelling allowed to estimate P–T conditions in the range T = 580–630 °C and P = 1.5–2.00 GPa for the formation of garnet core, between T = 620–690 °C and P = 2.0–2.3 GPa for garnet mantle, and within T = 650–700 °C and P = 1.4–2.1 GPa for garnet rim. The first part of the P–T path is characterized by a prograde increase in P and T in the eclogite facies that occurred between the growth of the garnet core and mantle. After the peak pressure, recorded by the garnet mantle composition, the rocks underwent moderate temperature increase and significant pressure decrease until they reach the peak temperature near to the eclogite/upper granulite‐facies transition, recorded by the garnet rim composition. The P–T trajectory proposed for the early stage of the metamorphic evolution of the kyanite‐bearing eclogites is similar to already existing observations from the Sardinian Low‐ to Medium‐Grade Metamorphic Complex and introduce new constraints on their prograde eclogite‐facies evolution. The role of the new prograde path is then discussed in the light of the Variscan orogen.
In‐vivo patellar tracking in individuals with patellofemoral pain and healthy individuals
Authors: Esfandiarpour Fateme , Lebrun Constance M. , Dhillon Sukhvinder , Boulanger Pierre 
Published: February 2018

ABSTRACTUnderstanding of the exact cause of patellofemoral pain has been limited by methodological challenges to evaluate in‐vivo joint motion. This study compared six degree‐of‐freedom patellar motion during a dynamic lunge task between individuals with patellofemoral pain and healthy individuals. Knee joints of eight females with patellofemoral pain and ten healthy females were imaged using a CT scanner in supine lying position, then by a dual‐orthogonal fluoroscope while they performed a lunge. To quantify patellar motion, the three‐dimensional models of the knee bones, reconstructed from CT scans, were registered on the fluoroscopy images using the Fluomotion registration software. At full knee extension, the patella was in a significantly laterally tilted (PFP: 11.77° ± 7.58° vs. healthy: 0.86° ± 4.90°; p = 0.002) and superiorly shifted (PFP: 17.49 ± 8.44 mm vs. healthy: 9.47 ± 6.16 mm, p = 0. 033) position in the patellofemoral pain group compared with the healthy group. There were also significant differences between the groups for patellar tilt at 45°, 60°, and 75° of knee flexion, and for superior‐inferior shift of the patella at 30° flexion (p ≤ 0.031). In the non‐weight‐bearing knee extended position, the patella was in a significantly laterally tilted position in the patellofemoral pain group (7.44° ± 6.53°) compared with the healthy group (0.71° ± 4.99°). These findings suggest the critical role of passive and active patellar stabilizers as potential causative factors for patellar malalignment/maltracking. Future studies should investigate the associations between patellar kinematics with joint morphology, muscle activity, and tendon function in a same sample for a thorough understanding of the causes of patellofemoral pain. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2193–2201, 2018.
Effect of Surface Dilatational Modulus on Bubble Generation in Visualized Pore‐Throat Models
Authors: Wang Yang , Ge Jijiang 
Published: February 2018

AbstractIn order to illustrate the effect of surface dilatational modulus on bubble break‐up, different pore‐throat visualized models were constructed using oil–wet poly(methyl methacrylate). Bubble generation was studied by comparing the snap‐off between lauroamide propyl betaine (LAB) with low surface dilatational modulus and LAB‐myristic acid with high surface dilatational modulus. In the homogeneous pore‐throat model, when bubbles of LAB flowed through the throat, only deformation occurred and no snap‐off was observed, while for bubbles of LAB‐myristic acid, repeated snap‐offs occurred. Experiments with isolated bubbles showed that a high surface dilatational modulus facilitates liquid flowing into the throat, which causes the snap‐off. Besides, the generated small bubbles contributed to the snap‐off of other following bubbles. In the pore‐throat model with large pores, the pores supplied enough space for bubbles passing through throat side by side, which facilitated the snap‐off.