bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transition‐Metal‐Complexed Cyclic [3]‐ and [4]Pseudorotaxanes Containing Rigid Ring‐and‐Filament Conjugates: Synthesis and Solution Studies
Authors: Voignier Julie , Frey Julien , Kraus Tomáš , Buděšínský Miloš , Cvačka Josef , Heitz Valérie , Sauvage Jean‐Pierre 
Published: March 2011

AbstractBy using the “gathering‐and‐threading” effect of copper(I) with rigid ring‐and‐string conjugates, daisy‐chain‐type [3]‐ and [4]pseudorotaxanes could be prepared in high yields. The organic fragment used consisted of a 2,9‐diphenyl‐1,10‐phenanthroline (dpp)‐containing ring attached to a coordinating filament capable of threading through the ring of another molecule by coordination to copper(I). The bidentate chelate introduced in the axis was also a 1,10‐phenanthroline (phen) derivative with two methyl groupsorthoto the nitrogen atoms of the phen unit. The organic component was prepared following a multistep strategy, one of the key steps being the attachment of the ring to the lateral axis. This connection was done by a condensation reaction between anorthodione located at the back of a ring‐incorporated phen and an aromatic aldehyde, which was the end‐function of the thread. An oxazole nucleus was obtained after the condensation, which provided a rigid connection between the ring and the axis. In this way, the coordination axes of the ring‐incorporated bidentate chelate and of the ligand belonging to the lateral filament were approximately orthogonal to one another. The design was such that the tetrameric complex, a [4]pseudorotaxane, seemed to be the most stable species, owing to the mutual geometrical arrangement of the filament and the ring. Various spectroscopic techniques, such as1H NMR spectroscopy, including DOSY, and electrospray ionization mass spectroscopy (ESI‐MS), clearly demonstrated that a mixture of cyclic [3]‐ and [4]pseudorotaxane was obtained; the proportions of both components depended on concentration and temperature. Copper(I) was not the only metal center leading to the formation of cyclic pseudorotaxanes. A similar effect was observed with silver(I) as the templating metal: quantitative formation of threaded species was observed, with a higher proportion of trimer over tetramer than in the copper(I) case. Concentration and temperature effects were investigated for both series of CuI‐ and AgI‐complexed threaded species showing that formation of the trimer was favored upon dilution or heating of the solution.
Microwave‐Assisted Aminocarbonylation of Ynamides by Using Catalytic [Fe3(CO)12] at Low Pressures of Carbon Monoxide
Authors: Pizzetti Marianna , Russo Adele , Petricci Elena 
Published: March 2011

AbstractThe microwave‐assisted aminocarbonylation of ynamides at low pressures of CO is reported. A new class of (E)‐acrylamides that are potentially suitable for several applications has been regioselectively synthesized after microwave irradiation for only 20 min by using eco‐friendly [Fe3(CO)12] as the catalyst precursor and triethylamine as the ligand. This transformation is atom economic as all reactants are used in stoichiometric quantities. Furthermore, the transformation is efficiently applied to the alkoxycarbonylation of alkynes as well. Moreover, running these reactions under microwave irradiation allows the simplification of the reaction conditions with remarkable reductions in time, temperature and gas pressure.
p16/ki‐67 dual‐stain cytology in the triage of ASCUS and LSIL Papanicolaou cytology
Authors: Schmidt Dietmar , Bergeron Christine , Denton Karin J , Ridder Ruediger ,   for the European CINtec Cytology Study Group
Published: March 2011

AbstractBACKGROUND:The objective of this study was to analyze the diagnostic performance of a newly established immunocytochemical dual‐stain protocol, which simultaneously detects p16INK4a and Ki‐67 expression in cervical cytology samples, for identifying high‐grade cervical intraepithelial neoplasia (CIN2+) in women with Papanicolaou (Pap) cytology results categorized as atypical squamous cells of undetermined significance (ASCUS) or low‐grade squamous intraepithelial lesions (LSIL).METHODS:Residual liquid‐based cytology material from 776 retrospectively collected ASCUS/LSIL cases that were available from a recent study evaluating p16 cytology and HPV testing were subjected to p16/Ki‐67 dual staining. The presence of 1 or more double‐immunoreactive cell(s) was regarded as a positive test outcome, irrespective of morphology. Test results were correlated to histology follow‐up.RESULTS:Sensitivity of p16/Ki‐67 dual‐stain cytology for biopsy‐confirmed CIN2+ was 92.2% (ASCUS) and 94.2% (LSIL), while specificity rates were 80.6% (ASCUS) and 68.0% (LSIL), respectively. Similar sensitivity/specificity profiles were found for both age groups of women aged <30 years versus women aged ≥30 years. Dual‐stain cytology showed comparable sensitivity, but significantly higher specificity, when compared with human papillomavirus (HPV) testing.CONCLUSIONS:The results of this study show that p16/Ki‐67 dual‐stain cytology provided a high sensitivity for the detection of underlying CIN2+ in women with ASCUS or LSIL Pap cytology results, comparable to the rates previously reported for HPV testing and p16 single‐stain cytology. However, the specificity of this morphology‐independent interpretation of p16/Ki‐67 dual‐stain cytology testing was further improved compared with the earlier p16 single‐stain cytology approach, which required morphology interpretation, and it is significantly higher when compared with HPV testing. Cancer (Cancer Cytopathol) 2011;. © 2011 American Cancer Society.
Infrared Spectrum of the Ag+–(Pyridine)2 Ionic Complex: Probing Interactions in Artificial Metal‐Mediated Base Pairing
Authors: Chakraborty Shamik , Dopfer Otto 
Published: March 2011

AbstractThe isolated pyridine–Ag+–pyridine unit (PyAg+Py) is employed as a model system to characterize the recently observed Ag+‐mediated base pairing in DNA oligonucleotides at the molecular level. The structure and infrared (IR) spectrum of the Ag+Py2 cationic complex are investigated in the gas phase by IR multiple‐photon dissociation (IRMPD) spectroscopy and quantum chemical calculations to determine the preferred metal‐ion binding site and other salient properties of the potential‐energy surface. The IRMPD spectrum has been obtained in the 840–1720 cm−1 fingerprint region by coupling the IR free electron laser at the Centre Laser Infrarouge d’Orsay (CLIO) with a Fourier‐transform ion cyclotron resonance (FT‐ICR) mass spectrometer equipped with an electrospray ionization source. The spectroscopic results are interpreted with quantum chemical calculations conducted at the B3LYP/aug‐cc‐pVDZ level. The analysis of the IRMPD spectrum is consistent with a σ complex, in which the Ag+ ion binds to the nitrogen lone pairs of the two Py ligands in a linear configuration. The binding motif of PyAg+Py in the gas phase is the same as that observed in Ag+‐mediated base pairing in solution. Ag+ bonding to the π‐electron system of the aromatic ring is predicted to be a substantially less‐favorable binding motif.
Afp::mCherry, a red fluorescent transgenic reporter of the mouse visceral endoderm
Authors: Viotti Manuel , Nowotschin Sonja , Hadjantonakis Anna‐Katerina 
Published: March 2011

AbstractSection through the intestine of a P3 (postnatal day 3) Afp::mCherry; Afp::GFP double transgenic mouse. Red and green fluorescent reporter‐expressing cells are located in the endoderm layer along villi, but excluded from the crypt stem cell zone. See the article by Viotti at al. in this issue.
Climate and land use controls over terrestrial water use efficiency in monsoon Asia
Authors: Tian Hanqin , Lu Chaoqun , Chen Guangsheng , Xu Xiaofeng , Liu Mingliang , Ren Wei , Tao Bo , Sun Ge , Pan Shufen , Liu Jiyuan 
Published: March 2011

AbstractMuch concern has been raised regarding how and to what extent climate change and intensive human activities have altered water use efficiency (WUE, amount of carbon uptake per unit of water use) in monsoon Asia. By using a process‐based ecosystem model [dynamic land ecosystem model (DLEM)], we examined effects of climate change, land use/cover change, and land management practices (i.e. irrigation and nitrogen fertilization) on WUE in terrestrial ecosystems of monsoon Asia during 1948–2000. Our simulations indicated that due to climate variability/change, WUE in the entire area decreased by 3·6% during the study period, with the largest decrease of 6·8% in the 1990s. Grassland was the most sensitive biome to a drying climate, with a decrease of 16·2% in WUE in the 1990s. Land conversion from natural vegetation to croplands, accounting for 79% of the total converted land areas, led to a decrease in WUE, with the largest decrease of 42% while forest was converted to cropland. In contrast, WUE increased by more than 50% while cropland was converted to natural vegetation. Simulated results also showed that intensive land management practices could alleviate the decrease in WUE induced by climate change and land conversion. Changes in WUE showed substantial spatial variation, varying from the largest decrease of over 50% in northwestern China and some areas of Mongolia to the largest increase of over 30% in western, southern China, and large areas of India. To adapt to climate change and sustain terrestrial ecosystem production, more attention ought to be paid to enhance water use efficiency through land use and management practices, especially in the drying areas. Copyright © 2011 John Wiley & Sons, Ltd.
Organization of complexity in water limited ecohydrology
Authors: Jenerette G. Darrel , Barron‐Gafford Greg A. , Guswa Andrew J. , McDonnell Jeffrey J. , Villegas Juan Camilo 
Published: March 2011

ABSTRACTWater limited ecohydrological systems (WLES), with their broad extent, large stores of global terrestrial carbon, potential for large instantaneous fluxes of carbon and water, sensitivity to environmental changes, and likely global expansion, are particularly important ecohydrological systems. Strong nonlinear responses to environmental variability characterize WLES, and the resulting complexity of system dynamics has challenged research focussed on general understanding and site specific predictions. To address this challenge our synthesis brings together current views of complexity from ecological and hydrological sciences to look towards a framework for understanding ecohydrological systems (in particular WLES) as complex adaptive systems (CAS). This synthesis suggests that WLES have many properties similar to CAS. In addition to exhibiting feedbacks, thresholds, and hysteresis, the functioning of WLES is strongly affected by self‐organization of both vertical and horizontal structure across multiple scales. As a CAS, key variables for understanding WLES dynamics are related to their potential for adaptation, resistance to variability, and resilience to state changes. Several essential components of CAS, including potential for adaptation and rapid changes between states, pose challenges for modelling and generating predictions of WLES. Model evaluation and predictable quantities may need to focus more directly on temporal or spatial variance in contrast to mean state values for success at understanding system‐level characteristics. How coupled climate and vegetation changes will alter available soil, surface and groundwater supplies, and overall biogeochemistry will reflect how self‐organizational ecohydrological processes differentially partition precipitation and overall net metabolic functioning. Copyright © 2011 John Wiley & Sons, Ltd.
Forest ecohydrological processes in a changing environment
Authors: Wei Xiaohua , Sun Ge , Vose James M. , Otsuki Kyoichi , Zhang Zhiqiang , Smetterm Keith 
Published: March 2011

AbstractThe papers in this issue are a selection of the presentations made at the second International Conference on Forests and Water in a Changing Environment. This special issue ‘Forest Ecohydrological Processes in a Changing Environment’ covers the topics regarding the effects of forest, land use and climate changes on ecohydrological processes across forest stand, watershed and regional spatial scales. Copyright © 2011 John Wiley & Sons, Ltd.
Two‐Step versus One‐Step Spin Transitions in Iron(II) 1D Chain Compounds
Authors: Bauer Wolfgang , Scherer Wolfgang , Altmannshofer Sandra , Weber Birgit 
Published: March 2011

AbstractEleven iron(II) 1D coordination polymers with the general formula [FeLeq(Lax)]·solvent were synthesised and characterised, where Leq = (E,E)‐{diethyl 2,2′‐[1,2‐phenylenebis(iminomethylidyne)]bis(3‐oxobutanato) (2‐)‐N,N′,O3,O3′} (L1) and {[3,3′]‐[1,2‐phenylenebis(iminomethylidyne)]bis(2,4‐pentane‐dionato)(2‐)‐N,N′,O2,O2′} (L2); Lax = 4,4′‐bipyridine (bipy), 1,2‐bis(4‐pyridyl)ethane (bpea) and 1,3‐bis(4‐pyridyl)propane (bppa) and solvent = MeOH, EtOH and toluene (Tol). [FeL1(bpea)]·MeOH (3·MeOH) shows an abrupt one‐step spin crossover with thermal hysteresis(27 K) and [FeL2(bppa)]·MeOH (2·MeOH), [FeL2(bpea)] (4), [FeL2(bpea)]·0.25MeOH (4·0.25MeOH) and [FeL1(bipy)]·MeOH (5·MeOH) show a two‐step spin transition with an IP at γHS ≈ 0.5 (IP is intermediate plateau and γHS is high‐spin mol fraction) and up to 50 K wide hysteresis loops (5·MeOH). [FeL1(bppa)] (1), [FeL2(bppa)]·EtOH (2·EtOH) and [FeL1(bpea)]·1.5Tol (3·1.5Tol) show an abrupt incomplete spin transition that stops at γHS ≈ 0.5; for [FeL1(bppa)]·0.25MeOH (1·0.25MeOH) and [FeL1(bpea)] (3), the spin transition is gradual and incomplete. The X‐ray crystal structures of six complexes were determined (1, 2·MeOH, 3·MeOH, 3·1.5Tol, 4·0.25MeOH and 5·MeOH). In the case of 4·0.25MeOH, the crystal structures for the HS and LS states were dertermined; for compounds 1, 2·MeOH and 3·1.5Tol, the crystal structure of the HS and the IP state was investigated. For all complexes, the iron(II) centre is located in a distorted octahedral coordination sphere. Each axially coordinated ligand “connects” two iron(II) centres, which results in the formation of extended 1D chains with varying structures from linear (bipy) over steplike (bpea) to zigzag (bppa). Analysis of the intermolecular interactions reveals that the hysteresis width depends on both the stiffness of the axial ligand and the number of intermolecular contacts, while zigzag chains support stepwise spin transitions.
Synthesis, Swelling, and Exfoliation of Microporous Lamellar Titanosilicate AM‐4
Authors: Casado Clara , Ambroj Diego , Mayoral Álvaro , Vispe Eugenio , Téllez Carlos , Coronas Joaquín 
Published: March 2011

AbstractAM‐4 is a layered porous titanosilicate built from TiO6 and SiO4 polyhedra. An improved synthesis of AM‐4 crystalsenabling control of particle size by secondary growth and reducing synthesis time is presented. A new material, UZAR‐S2, has been obtained by exfoliation of the smaller AM‐4. The exfoliation consists of proton exchange with acetic acid, intercalation with nonylamine, and final activation by washing with HCl/water/ethanol. Besides XRD, TEM, N2 adsorption, FTIR, and UV/Vis characterization highlighting the delaminated character of UZAR‐S2, CO2 adsorption was also measured.
A Convenient Road to 1‐Chloropentacycloundecanes – A Joint Experimental and Computational Investigation
Authors: Sharapa Dmitry I. , Gayday Alexander V. , Mitlenko Alena G. , Levandovskiy Igor A. , Shubina Tatyana E. 
Published: March 2011

AbstractAn efficient synthetic strategy to obtain 1‐chloro‐Cs‐trishomocubane and 1‐chloro‐D3‐trishomocubane is described. 1‐Chloro‐Cs‐trishomocubane is synthesized by a regioselective Diels–Alder reaction, and B3PW91/6‐31G(d,p) calculations offer a plausible explanation of the reaction mechanism. Surprisingly, 1‐chloro‐Cs‐trishomocubane does not undergo an acid‐catalyzed rearrangement to form 1‐chloro‐D3‐trishomocubane and was obtained by chlorosulfation of Cookson's diketone. A possible mechanism of the reaction involving the formation of Cs‐ and D3‐trishomocubane nonclassical cations was proposed on the basis of a mechanistic [B3PW91/6‐31G(d,p) and MP2/cc‐pVDZ] study.
Titanium(IV) Chloride‐Mediated Carbocyclization of 1,6‐Enynes: Selective Synthesis of 3‐Azabicyclo[3.1.0]hexanes and Functionalized Allenes by Controlling the Reaction Temperature
Authors: Zhang Zhen , Shi Min 
Published: March 2011

Abstract1,6‐Enynes can be transformed into 3‐azabicyclo[3.1.0]hexanes and functionalized allenes in moderate to good yields along with moderate to high diastereoselectivities by controlling the reaction temperature in the presence of titanium(IV) chloride. A plausible mechanism is proposed.
Growth by extension, and reworking, of a south‐western Kalahari linear dune
Authors: Telfer Matt W. 
Published: March 2011

ABSTRACTOptically stimulated luminescence (OSL) dating studies of linear (longitudinal) dunes have been used extensively to elucidate late Quaternary environments and climates in arid or formerly arid regions, yet understanding of the development of such dunes is incomplete. In particular, conflicting opinions have been presented regarding the propensity of linear dunes to migrate laterally, the degree to which they rework their own sediment during accumulation and whether they form primarily by extension, as opposed to lateral sand movement from adjacent interdunes. This study focuses on this last point, although the importance of the other controversies is discussed in context. A simple linear dune in the south‐western Kalahari, which has a prominent termination on a pan (playa) surface, provides an opportunity to directly test hypotheses of dune extension. Chronostratigraphy along a ~600 m transect along the crest of the dune, constrained by 42 OSL ages, reveals that the dune grew by extension on occasions in the late Pleistocene and early Holocene, but has also been subject to reworking along its length, which has continued until recent times. Dune development by extensional growth is suggested to operate under environmental conditions more conducive to net accumulation, whereas reworking is largely independent of conditions throughout the last ~18 ka, and may represent seasonal fluctuations in the position of the dune crest. The relative significance of these two modes of development is suggested to be a key control on the efficacy of linear dunes as archives of environmental and climatic change. Copyright © 2011 John Wiley & Sons, Ltd.
Price–Dividend Ratios and Stock Price Predictability
Authors: Wu Jyh‐Lin , Hu Yu‐Hau 
Published: March 2011

ABSTRACTA long‐standing puzzle to financial economists is the difficulty of outperforming the benchmark random walk model in out‐of‐sample contests. Using data from the USA over the period of 1872–2007, this paper re‐examines the out‐of‐sample predictability of real stock prices based on price–dividend (PD) ratios. The current research focuses on the significance of the time‐varying mean and nonlinear dynamics of PD ratios in the empirical analysis. Empirical results support the proposed nonlinear model of the PD ratio and the stationarity of the trend‐adjusted PD ratio. Furthermore, this paper rejects the non‐predictability hypothesis of stock prices statistically based on in‐ and out‐of‐sample tests and economically based on the criteria of expected real return per unit of risk. Copyright © 2011 John Wiley & Sons, Ltd.
Mortgagees and receivers exercising powers of sale – An English and Australian comparative analysis
Authors: Werner Carl 
Published: March 2011

AbstractFor many years, the English and Australian courts have been at odds in their respective treatment of the obligations imposed on mortgagees and receivers when exercising powers of sale. Indeed, a Full Court of the Federal Court of Australia has recently confirmed that the more onerous test under English law, as enunciated in Cuckmere Brick,1 does not reflect the current general law in Australia.2 This paper examines the current state of the law in England and Australia and argues that the widely held belief that mortgagees and receivers in Australia are under a lesser duty than their English counterparts is largely misconceived. Copyright © 2011 John Wiley & Sons, Ltd.
The tissue response to photopolymerized PEG‐p(HPMAm‐lactate)‐based hydrogels
Authors: Censi Roberta , van Putten Sander , Vermonden Tina , di Martino Piera , van Nostrum Cornelus F. , Harmsen Martin C. , Bank Ruud A. , Hennink Wim E. 
Published: March 2011

AbstractHydrogels are three‐dimensional networks of crosslinked hydrophilic polymers widely used for protein delivery and tissue engineering. To be eligible for in vivo applications, the hydrogels should not evoke an adverse tissue response. In this study the angiogenic and inflammatory responses in vivo after implantation of photopolymerized thermosensitive poly(hydroxypropyl methacrylamide lactate)‐poly(ethyl copolymer hydrogels are investigated. Hydrogels consisting of polymers with different crosslink densities were subcutaneously implanted in Balb/c mice and histological evaluation of the tissue response was performed. The implants showed an acute and localized inflammatory reaction upon implantation, mainly characterized by a strong infiltration of granulocytes. The acute inflammatory reaction was followed by a milder chronic inflammation which was characterized by infiltration of macrophages and persistent but decreasing levels of granulocytes. The number of macrophages and blood vessels was associated with the biodegradation and resorption of the biomaterial and increased in time as the degradation of the materials progressed. The observed degradation rates in vivo correlated well with previously observed in vitro degradation rates, which suggests that hydrolysis is the main mechanism governing the degradation. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011.
Salicylic acid‐derived poly(anhydride‐ester) electrospun fibers designed for regenerating the peripheral nervous system
Authors: Griffin Jeremy , Delgado‐Rivera Roberto , Meiners Sally , Uhrich Kathryn E. 
Published: March 2011

AbstractContinuous biomaterial advances and the regenerating potential of the adult human peripheral nervous system offer great promise for restoring full function to innervated tissue following traumatic injury via synthetic nerve guidance conduits (NGCs). To most effectively facilitate nerve regeneration, a tissue engineering scaffold within a conduit must be similar to the linear microenvironment of the healthy nerve. To mimic the native nerve structure, aligned poly(lactic‐co‐glycolic acid)/bioactive polyanhydride fibrous substrates were fabricated through optimized electrospinning parameters with diameters of 600 ± 200 nm. Scanning electron microscopy images show fibers with a high degree of alignment. Schwann cells and dissociated rat dorsal root ganglia demonstrated elongated and healthy proliferation in a direction parallel to orientated electrospun fibers with significantly longer Schwann cell process length and neurite outgrowth when compared to randomly orientated fibers. Results suggest that an aligned polyanhydride fiber mat holds tremendous promise as a supplement scaffold for the interior of a degradable polymer NGC. Bioactive salicylic acid‐based polyanhydride fibers are not limited to nerve regeneration and offer exciting promise for a wide variety of biomedical applications. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011.