bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pyrazole‐Stabilized Dinuclear Palladium(II) Chalcogenolates Formed by Oxidative Addition of Bis[2‐(4‐bromopyrazol‐1‐yl)ethyl] Dichalcogenides to Palladium(II) – Tailoring of Pd–S/Se Nanoparticles
Authors: Nayan Sharma Kamal , Joshi Hemant , Prakash Om , Sharma Alpesh K. , Bhaskar Renu , Singh Ajai K. 
Published: September 2015

AbstractBis[2‐(4‐bromopyrazol‐1‐yl)ethyl] disulfide and diselenideL1andL2were synthesized by the reactions of 4‐bromo‐1‐(2‐chloroethyl)‐1H‐pyrazole with the in situ generated Na2S2and Na2Se2. The reactions ofL1andL2with 2 equiv. of [PdCl2(CH3CN)2] in CH3CN at 70 °C proceed through an oxidative addition/reductive elimination sequence to the PdIIcenter to form the chalcogenolato‐bridged dinuclear palladium(II) complexes [Pd2Cl2(μ‐EN)2] [1(E = S) and2(E = Se); EN = 2‐(4‐bromopyrazol‐1‐yl)ethanechalcogenolate]. The reactions of1and2with CH3CN and AgBF4resulted in the formation of [Pd2(CH3CN)2(μ‐EN)2]·2BF4(3and4). CompoundsL1,L2, and their complexes1–4have been characterized through1H,13C{1H}, and77Se{1H} nuclear magnetic resonance (NMR) spectroscopy; infrared (IR) spectroscopy; and high‐resolution mass spectrometry (HRMS). The single‐crystal X‐ray structures of2–4have revealed distorted square‐planar geometries around the Pd center in each case. The Pd–S and Pd–Se bond lengths are in the ranges 2.277(2)–2.296(2) and 2.372(9)–2.3971(17) Å, respectively. Single‐source precursor routes for the synthesis of palladium chalcogenide nanoparticles (NPs) have been developed by the thermolyses of1–4in 1:1 mixtures of oleic acid (OA) and 1‐octadecene (ODE). Pd17Se15NPs were formed from both PdIIselenolates2and4, whereas Pd4S NPs and a mixture of Pd16S7(ca. 68 %) and PdS (ca. 32 %) NPs were obtained from PdIIthiolates1and3, respectively. Transmission electron microscopy (TEM), scanning electron microscopy with energy‐dispersive X‐ray spectroscopy (SEM‐EDX), and powder X‐ray diffraction (PXRD) have been used to authenticate the NPs. X‐ray photoelectron spectroscopy (XPS) studies on the NPs have revealed that there is a charge transfer from Pd to S/Se. The compositions of the NPs determined from XPS are consistent with the PXRD results.
Bioinspired Nanoparticle‐Assembly Route to a Hybrid Scaffold: Designing a Robust Heterogeneous Catalyst for Asymmetric Dihydroxylation of Olefins
Authors: Shilpa Nagaraju , Manna Joydeb , Rana Rohit Kumar 
Published: September 2015

AbstractA hierarchical polyamine‐silica structure is shown to encase osmate ions resulting in robust and reusable catalysts for asymmetric dihydroxylation of olefins with a high TON (>700). Whilst the polypeptide and related polyamines resembling a proteinaceous matrix in biosilica nanostructures preserve the osmate as the active centre, the surrounding assembly of silica nanoparticles imparts stability and textural properties to the catalyst. This confinement of osmate in the microsphere leads to higher catalytic activity and enantioselectivity for a variety of olefins as the substrate. The hybrid nature of the catalyst not only allows for the usage of various solvent systems, but also provides a means to be integrated with multi‐components/functions for tuning the activity, catalysis separation and reusability. Interestingly, the presence of polyamine makes the catalyst retain its activity even in the presence of chelating acids like citrate that are known to diminish enantioselectivity.
In Silico Study on Chemical Properties and Reactivity of Enal Derivatives
Authors: Borosky Gabriela L. , Laali Kenneth K. 
Published: September 2015

AbstractThe chemical properties and reactivity of enals were explored by means of quantum chemical methods of calculation. The substituent effects were examined by analyzing the formation of oxonium and carbenium intermediates via protonation reactions as models for activation of enals. Considering the nucleophilic addition of organometallic reagents to enals as an important synthetic step, formation and reactivity of the anionic derived species were modeled computationally for the bis‐silylated enals and their subsequent reaction with model electrophiles, in order to gain insight into the regio‐ and stereoselectivity previously observed in electrophilic additions. Silylated enals exhibited interesting features based on the electronic and steric properties of silyl substituents. The present model computations could assist in the development of new synthetic applications for this class of compounds as they find wider synthetic application.
Enantioselective Installation of Quaternary Centers in Cyclic Oxonitriles
Authors: Gunes Yakup , Arcelik Nejat , Sahin Ertan , Fleming Fraser F. , Altundas Ramazan 
Published: September 2015

AbstractQuaternary centers are rapidly and selectively installed in a series of seven‐membered and bridged cyclic oxonitriles through conjugate addition of an alkoxide to chloroalkenenitriles, followed by a Claisen rearrangement. Using this strategy, the stereogenic information of the carbinol in secondary allylic alcohols is transferred to the newly generated quaternary center. Experimentally, the sequence rapidly gives alkyl cyanocycloheptanones and bicycloalkanonecarbonitriles in good yield and with high selectivity, in a single synthetic operation.
Comparative Analysis of Fluorine‐Directed Glycosylation Selectivity: Interrogating C2 [OH → F] Substitution in d‐­Glucose and d‐Galactose
Authors: Santschi Nico , Gilmour Ryan 
Published: September 2015

AbstractThe influence of C2 [OH → F] substitution on the stereochemical course of chemical glycosylation was interrogated in both D‐glucose and its C4 epimer D‐galactose. Molecular editing at C2 and configurational inversion at C4 were simultaneously investigated by variable‐temperature glycosylation studies of both systems. Extrapolation of the differences in enthalpic (ΔΔHβα‡) and entropic (ΔΔSβα‡) contributions that discriminate these closely similar systems revealed that deoxofluorination at the C2 position induces an enthalpic bias that augments β‐stereoselection. Intriguingly, the enhanced stereoselectivity of the C4 epimer D‐galactose was found to be entropic in nature. Given the prominence of these scaffolds in chemical biology, delineating the factors that underpin selectivity will be critical in developing novel glycosylation methods and in rationalizing differences with the natural systems post facto.
One ring to rule them all: Master discourses of enlightenment—and racism—from colonial to contemporary New Zealand
Authors: Liu James H. , Robinson Angela R. 
Published: September 2015

AbstractWe interrogated historical continuity and change in discourses of enlightenment and racism through the analysis of 160 years of New Zealand Speeches from the Throne (1854–2014, 163 speeches). Enlightenment discourses of benevolence and perfectibility were prevalent in all periods, much more so than racism. ‘Old‐fashioned’ racism took the form of an assumed civilizational superiority (including accusations of ‘barbarism’) during colonization, with ‘modern’ racism taking forms like blaming Māori for not ‘productively’ using the land. Both declined to almost zero by the 20th century, undermining the idea of ‘old‐fashioned’ versus ‘modern’ racism. Utilitarian discourses peaked in the late 19th to early 20th centuries as justification for Māori land alienation. ‘Master discourses of enlightenment’ consisted of a central core of social representations that changed at the periphery, with a gradual expansion of symbolic inclusion of Māori in discourses of national identity to the point where biculturalism is the dominant discourse for elites today.
Assessing the risk to green sturgeon from application of imidacloprid to control burrowing shrimp in Willapa Bay, Washington—Part II: Controlled exposure studies
Authors: Frew John A. , Grue Christian E. 
Published: September 2015

Abstract

The activities of 2 species of burrowing shrimp have a negative impact on the growth and survival of oysters reared on intertidal mudflats in Willapa Bay and Grays Harbor, Washington (USA). To maintain viable harvests, oyster growers proposed the application of the neonicotinoid insecticide imidacloprid onto harvested beds for the control of burrowing shrimp. In test applications, water column concentrations of imidacloprid were relatively low and dissipated rapidly. The foraging activities of the green sturgeon (listed in the US Endangered Species Act) could result in exposure to higher, more sustained imidacloprid concentrations within sediment porewater and from the consumption of contaminated shrimp. Controlled experiments were conducted using surrogate white sturgeon to determine acute and chronic effect concentrations, to examine overt effects at more environmentally realistic concentrations and durations of exposure, and to assess chemical depuration. The 96-h median lethal concentration was 124 mg L–1, and the predicted 35-d no-observed-adverse-effect concentration was 0.7 mg L–1. No overt effects were observed following environmentally relevant exposures. Imidacloprid half-life in plasma was greater than 32 h. Measured concentrations of imidacloprid in porewater were significantly lower than the derived acute and chronic effect concentrations for white sturgeon. Exposure risk quotients were calculated using the effect concentrations and estimated environmental exposure. The resulting values were considerably below the level of concern for direct effects from either acute or chronic exposure to an endangered species. Environ Toxicol Chem 2015;34:2542–2548. © 2015 SETAC
New record in Catasetum (Orchidaceae) for the State of Ceará, Brazil
Authors: Petini‐Benelli Adarilda , Farias Castro Antônio Sérgio 
Published: September 2015

AbstractIn this paper we report the discovery of Catasetum planiceps, in the Serra da Ibiapaba, as a new and important event for the flora of Ceará, Brazil. The species was recorded growing as a rupicolous herb in vegetation called ‘Macambiral’, which is an area of ‘brejo forest’, in the Serra da Ibiapaba in the municipality of Ipueiras. The vegetation in this area is a mixture of semi‐deciduous tropical moist forests and ‘carrasco’ vegetation, forming an important ecotone in the caatinga vegetational domain. Collected material was deposited in the EAC and UFMT herbaria and a sample was sent to the DNA bank of the Laboratório de Sistemática e Ecologia Molecular de Plantas of the Universidade Federal do Paraná (Curitiba, Paraná State, Brazil). This new record is of great importance because the type of habitat in which it was registered is very different from that originally described for this species. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Taxonomic study of the genus Chamaesiphon (Chroococcales: Cyanoprokaryota) reported from India with two new distributional records
Authors: Das Sudipta Kumar 
Published: September 2015

AbstractThere were only 9 taxa of Chamaesiphon A. Braun & Grunow, reported so far from India. This includes 6 species and 3 varieties. In the present study, two species of genus Chamaesiphon i.e. C. amethystinus and C. polonicus were reported from the Eastern Himalayas, as new records from India. Further, a taxonomic key to the Indian taxa of the genus Chamaesiphon along with their distribution in India as well as the globe have been provided. The taxonomic status of two endemic species was also evaluated. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modeling thermal conductivity in silicon nanowires
Authors: Martin C. S. , Ariza M. P. , Ortiz M. 
Published: September 2015

AbstractThe complexity of heat transport in silicon nanowires (SiNWs) and, specifically, its dependence on temperature and the nanowire diameter, is beyond continuum models of heat conduction and necessitate consideration of atomic‐level heat‐conduction models. In this work, we specifically aim to ascertain the ability of models based on non‐equilibrium statistical mechanics to reproduce the observed anisotropy, temperature and size dependence of the thermal conductivity of SiNWs. In this approach, the atomic‐level kinetic relations are regarded as empirical and subject to modeling. Within this framework, we find that a simple model, based on the introduction of a thin amorphous layer at the surface of the SiNWs, yields effective thermal conductivities that are in excellent agreement with the experimental data over a range of temperatures and diameters. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Computational homogenization of nano‐materials accounting for size effects via surface elasticity
Authors: Javili Ali , Chatzigeorgiou George , McBride Andrew T. , Steinmann Paul , Linder Christian 
Published: September 2015

AbstractThe objective of this contribution is to establish a first‐order computational homogenization framework for micro‐to‐macro transitions of porous media that accounts for the size effects through the consideration of surface elasticity at the microscale. Although the classical (firstorder) homogenization schemes are well established, they are not capable of capturing the well‐known size effects in nano‐porous materials. In this contribution we introduce surface elasticity as a remedy to account for size effects within a first‐order homogenization scheme. This proposition is based on the fact that surfaces are no longer negligible at small scales.Following a standard first‐order homogenization ansatz on the microscopic motion in terms of the macroscopic motion, a Hill‐type averaging condition is used to link the two scales. The averaging theorems are revisited and generalized to account for surfaces. In the absence of surface energy this generalized framework reduces to classical homogenization. The influence of the length scale is elucidated via a series of numerical examples performed using the finite element method. The numerical results are compared against the analytical ones at small strains for tetragonal and hexagonal microstructures. Furthermore, numerical results at small strains are compared with those at finite strains for both microstructures. Finally, it is shown that there exists an upper bound for the material response of nano‐porous media. This finding surprisingly restricts the notion of “smaller is stronger”. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Homogenization and multiscale stability analysis in finite magneto‐electro‐elasticity
Authors: Miehe Christian , Vallicotti Daniel , Teichtmeister Stephan 
Published: September 2015

AbstractSoft matter electro‐elastic, magneto‐elastic and magneto‐electro‐elastic composites exhibit coupled material behavior at large strains. Examples are electro‐active polymers and magnetorheological elastomers, which respond by a deformation to applied electric or magnetic fields, and are used in advanced industrial environments as sensors and actuators. Polymer‐based magneto‐electric‐elastic composites are a new class of tailor‐made materials with promising future applications. Here, a magneto‐electric coupling effect is achieved as a homogenized macro‐response of the composite with electro‐active and magneto‐active constituents. These soft composite materials show different types of instability phenomena, which even might be exploited for future enhancement of their performance. This covers micro‐structural instabilities, such as buckling of micro‐fibers or particles, as well as material instabilities in the form of limit‐points in the local constitutive response. Here, the homogenization‐based scale bridging links long wavelength micro‐structural instabilities to material instabilities at the macro‐scale. This work outlines a framework of an energy‐based homogenization in electro‐magneto‐mechanics, which allows a tracking of postcritical solution paths such as those related to pull‐in instabilities. Representative simulations demonstrate a tracking of inhomogenous composites, showing the development of postcritical zones in the microstructure and a possible instable homogenized material response. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Higher‐order quasicontinuum methods for elastic and dissipative lattice models: uniaxial deformation and pure bending
Authors: Beex L.A.A. , Rokoš O. , Zeman J. , Bordas S.P.A. 
Published: September 2015

AbstractThe quasicontinuum (QC) method is a numerical strategy to reduce the computational cost of direct lattice computations ‐ in this study we achieve a speed up of a factor of 40. It has successfully been applied to (conservative) atomistic lattices in the past, but using a virtualpower statement it was recently shown that QC approaches can also be used for spring and beam lattice models that include dissipation. Recent results have shown that QC approaches for planar beam lattices experiencing in‐plane and out‐of‐plane deformation require higherorder interpolation. Higher‐order QC frameworks are scarce nevertheless. In this contribution, the possibilities of a second‐order and third‐order QC framework are investigated for an elastoplastic spring lattice. The higher‐order QC frameworks are compared to the results of the direct lattice computations and to those of a linear QC scheme. Examples are chosen so that both a macroscale and a microscale quantity influences the results. The two multiscale examples focused on are (i) macroscopically prescribed uniaxial deformation and (ii) macroscopically prescribed pure bending. Furthermore, the examples include an individual inclusion in a large lattice and hence, are concurrent in nature. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Temporal stability of network centrality in control and default mode networks: Specific associations with externalizing psychopathology in children and adolescents
Authors: Sato João Ricardo , Biazoli Claudinei Eduardo , Salum Giovanni Abrahão , Gadelha Ary , Crossley Nicolas , Satterthwaite Theodore D. , Vieira Gilson , Zugman André , Picon Felipe Almeida , Pan Pedro Mario , Hoexter Marcelo Queiroz , Anés Mauricio , Moura Luciana Monteiro , Del'aquilla Marco Antonio Gomes , Amaro Edson , McGuire Philip , Lacerda Acioly L.T. , Rohde Luis Augusto , Miguel Euripedes Constantino , Jackowski Andrea Parolin , Bressan Rodrigo Affonseca 
Published: September 2015

AbstractAbnormal connectivity patterns have frequently been reported as involved in pathological mental states. However, most studies focus on “static,” stationary patterns of connectivity, which may miss crucial biological information. Recent methodological advances have allowed the investigation of dynamic functional connectivity patterns that describe non‐stationary properties of brain networks. Here, we introduce a novel graphical measure of dynamic connectivity, called time‐varying eigenvector centrality (tv‐EVC). In a sample 655 children and adolescents (7–15 years old) from the Brazilian “High Risk Cohort Study for Psychiatric Disorders” who were imaged using resting‐state fMRI, we used this measure to investigate age effects in the temporal in control and default‐mode networks (CN/DMN). Using support vector regression, we propose a network maturation index based on the temporal stability of tv‐EVC. Moreover, we investigated whether the network maturation is associated with the overall presence of behavioral and emotional problems with the Child Behavior Checklist. As hypothesized, we found that the tv‐EVC at each node of CN/DMN become more stable with increasing age (P < 0.001 for all nodes). In addition, the maturity index for this particular network is indeed associated with general psychopathology in children assessed by the total score of Child Behavior Checklist (P = 0.027). Moreover, immaturity of the network was mainly correlated with externalizing behavior dimensions. Taken together, these results suggest that changes in functional network dynamics during neurodevelopment may provide unique insights regarding pathophysiology.Hum Brain Mapp 36:4926–4937, 2015. ©2015 Wiley Periodicals, Inc.
Controlled Growth of Colloidal Gold Nanoparticles: Single‐Crystalline versus Multiply‐twinned Particles
Authors: Carbó‐Argibay Enrique , Rodríguez‐González Benito 
Published: September 2015

AbstractGold nanocrystals with well‐defined shapes are becoming more crucial in application fields as diverse as catalysis, plasmonics, sensing, drug delivery, and therapeutics. To accomplish real applications on a large scale, a tight control over the size and geometry of the nanoparticles is essential. During the last decade, a new view has emerged: the planning of the properties of nanoparticles based on the control of their morphology. This rational design of particles with desired properties requires strategies to control the nucleation and growth processes. This review provides an overview of applications, properties, characterization, and procedures for the growth of nanoparticles with well‐defined shapes, emphasizing the differences between the controlled growth of single‐crystal and twinned gold nanoparticles.
Managing Osteoporosis in Patients on Long-Term Bisphosphonate Treatment: Report of a Task Force of the American Society for Bone and Mineral Research
Authors: Adler Robert A , El-Hajj Fuleihan Ghada , Bauer Douglas C , Camacho Pauline M , Clarke Bart L , Clines Gregory A , Compston Juliet E , Drake Matthew T , Edwards Beatrice J , Favus Murray J , Greenspan Susan L , McKinney Ross , Pignolo Robert J , Sellmeyer Deborah E 
Published: September 2015

ABSTRACT

Bisphosphonates (BPs) are the most commonly used medications for osteoporosis. This ASBMR report provides guidance on BP therapy duration with a risk-benefit perspective. Two trials provided evidence for long-term BP use. In the Fracture Intervention Trial Long-term Extension (FLEX), postmenopausal women receiving alendronate for 10 years had fewer clinical vertebral fractures than those switched to placebo after 5 years. In the HORIZON extension, women who received 6 annual infusions of zoledronic acid had fewer morphometric vertebral fractures compared with those switched to placebo after 3 years. Low hip T-score, between –2 and –2.5 in FLEX and below –2.5 in HORIZON extension, predicted a beneficial response to continued therapy. Hence, the Task Force suggests that after 5 years of oral BP or 3 years of intravenous BP, reassessment of risk should be considered. In women at high risk, for example, older women, those with a low hip T-score or high fracture risk score, those with previous major osteoporotic fracture, or who fracture on therapy, continuation of treatment for up to 10 years (oral) or 6 years (intravenous), with periodic evaluation, should be considered. The risk of atypical femoral fracture, but not osteonecrosis of the jaw, clearly increases with BP therapy duration, but such rare events are outweighed by vertebral fracture risk reduction in high-risk patients. For women not at high fracture risk after 3 to 5 years of BP treatment, a drug holiday of 2 to 3 years can be considered. The suggested approach for long-term BP use is based on limited evidence, only for vertebral fracture reduction, in mostly white postmenopausal women, and does not replace the need for clinical judgment. It may be applicable to men and patients with glucocorticoid-induced osteoporosis, with some adaptations. It is unlikely that future trials will provide data for formulating definitive recommendations. © 2015 American Society for Bone and Mineral Research.