bluuebunny/crossref_metadata_2025_split huggingface dataset:
Control of Chiral Nanostructures by Self‐Assembly of Designed Amphiphilic Peptides and Silica Biomineralization
Authors: Huang Zhehao , Yao Yuan , Han Lu , Che Shunai 
Published: October 2014

AbstractPeptides, the fundamental building units of biological systems, are chiral in molecular scale as well as in spatial conformation. Shells are exquisite examples of well‐defined chiral structures produced by natural biomineralization. However, the fundamental mechanism of chirality expressed in biological organisms remains unclear. Here, we present a system that mimics natural biomineralization and produces enantiopure chiral inorganic materials with controllable helicity. By tuning the hydrophilicity of the amphiphilic peptides, the chiral morphologies and mesostructures can be changed. With decreasing hydrophilicity of the amphiphilic peptides, we observed that the nanostructures changed from twisted nanofibers with a hexagonal mesostructure to twisted nanoribbons with a lamellar mesostructure, and the extent of the helicity decreased. Defining the mechanism of chiral inorganic materials formed from peptides by noncovalent interactions can improve strategies toward the bottom‐up synthesis of nanomaterials as well as in the field of bioengineering.
Phosphorescent Polymeric Nanoparticles by Coordination Cross‐Linking as a Platform for Luminescence Imaging and Photodynamic Therapy
Authors: Lu Yang , Xue Fengfeng , Zhou Zhiguo , Shi Min , Yan Yuping , Qin Lijie , Yang Hong , Yang Shiping 
Published: October 2014

AbstractWater‐soluble phosphorescent polymeric nanoparticles with an average diameter of approximately 100 nm were synthesized by a coordination cross‐linking reaction. The pyridine blocks in poly(4‐vinyl pyridine‐b‐ethylene oxide) (P4VP‐b‐PEO) were cross‐linked by the iridium chloride‐bridged dimer in DMF solution. Owing to the presence of an iridium complex with different ligands in the core of the polymeric nanoparticles, NP‐1, NP‐2, and NP‐3 showed bright green, yellow, and red phosphorescence, respectively. PEG chains in the shell gave the polymeric nanoparticles solubility and biocompatibility, which was confirmed by an MTT assay using HeLa cells as a model cancer cell line. The flow cytometry and laser confocal fluorescence microscopy results revealed NP‐2, as an example, could be effectively uptaken by HeLa cells. Therefore, these polymeric nanoparticles can be used as luminescent probes for living cells. In addition, 1O2 could be effectively generated in the presence of NP‐2 upon irradiation with visible light (λ>400 nm, 300 mW cm−2), which was confirmed by a clear decrease in the fluorescence intensity of 9,10‐dimethylanthracene (DMA). After incubation with NP‐2 at a concentration of 200 μg mL−1 for 6 h, approximately 90 % of HeLa cells were effectively ablated upon irradiation with visible light for only 10 min, indicating the potential for photodynamic therapy with polymeric nanoparticles.
Phosphine‐Free Stille–Migita Chemistry for the Mild and Orthogonal Modification of DNA and RNA
Authors: Krause André , Hertl Alexander , Muttach Fabian , Jäschke Andres 
Published: October 2014

AbstractAn optimized catalyst system of [Pd2(dba)3] and AsPh3 efficiently catalyzes the Stille reaction between a diverse set of functionalized stannanes and halogenated mono‐, di‐ and oligonucleotides. The methodology allows for the facile conjugation of short and long nucleic acid molecules with moieties that are not compatible with conventional chemical or enzymatic synthesis, among them acid‐, base‐, or fluoride‐labile protecting groups, fluorogenic and synthetically challenging moieties with good to near‐quantitative yields. Notably, even azides can be directly introduced into oligonucleotides and (deoxy)nucleoside triphosphates, thereby giving direct access to “clickable” nucleic acids.
Experimental and Computational Evidence for the Mechanism of Intradiol Catechol Dioxygenation by Non‐Heme Iron(III) Complexes
Authors: Jastrzebski Robin , Quesne Matthew G. , Weckhuysen Bert M. , de Visser Sam P. , Bruijnincx Pieter C. A. 
Published: October 2014

AbstractCatechol intradiol dioxygenation is a unique reaction catalyzed by iron‐dependent enzymes and non‐heme iron(III) complexes. The mechanism by which these systems activate dioxygen in this important metabolic process remains controversial. Using a combination of kinetic measurements and computational modelling of multiple iron(III) catecholato complexes, we have elucidated the catechol cleavage mechanism and show that oxygen binds the iron center by partial dissociation of the substrate from the iron complex. The iron(III) superoxide complex that is formed subsequently attacks the carbon atom of the substrate by a rate‐determining CO bond formation step.
ChemInform Abstract: Oligomeric Rare‐Earth Metal Cluster Complexes with Endohedral Transition Metal Atoms.
Authors: Steinberg Simon , Zimmermann Sina , Bruehmann Matthias , Meyer Eva , Rustige Christian , Wolberg Marike , Daub Kathrin , Bell Thomas , Meyer Gerd 
Published: October 2014

AbstractComproportionation reactions of LnX3 (Ln: Sc, Y, La, Gd, Tb, Dy, Ho and X: Cl, Br, I) with the respective rare‐earth metals Ln and transition metals M (M: Ru, Rh, Os, Ir, Fe, Co) at 800—1050 °C leads to the formation of 19 new compounds.
Selector Screening for Enantioseparation of dl‐α‐Methyl Phenylglycine Amide by Liquid–Liquid Extraction
Authors: Schuur Boelo , Blahušiak Marek , Vitasari Caecilia R. , Gramblička Michal , De Haan André B. , Visser Ton J. 
Published: October 2014

AbstractEnantioseparation through liquid extraction technology is an emerging field, e.g., enantioseparations of amino acids (and derivatives thereof), amino alcohols, amines, and carboxylic acids have been reported. Often, when a new selector is developed, the versatility of substrate scope is investigated. From an industrial point of view, the problem is typically approached the other way around, and for a target racemate, a selector needs to be found in order to accomplish the desired enantioseparation. This study presents such a screening approach for the separation of the enantiomers of dl‐α‐methyl phenylglycine amide (dl‐α‐MPGA), a model amide racemate with high industrial relevance. Chiral selectors that were reported for other classes of racemates were investigated, i.e., several macrocyclic selectors and Pd‐BINAP complexes. It appeared very challenging to obtain both high extraction yields and good enantioselectivity for most selectors, but Pd‐BINAP‐based selectors performed well, with enantioselectivities up to 7.4 with an extraction yield of the desired enantiomer of 95.8%. These high enantioselectivities were obtained using dichloromethane as solvent. Using less volatile chlorobenzene or 1‐chloropentane, reasonable selectivities of up to 1.7 were measured, making these the best alternative solvents for dichloromethane. Chirality 27:123–130, 2015. © 2014 Wiley Periodicals, Inc.
Is High‐Intensity Statin Therapy Associated With Lower Statin Adherence Compared With Low‐ to Moderate‐Intensity Statin Therapy? Implications of the 2013 American College of Cardiology/American Heart Association Cholesterol Management Guidelines
Authors: Virani Salim S. , Woodard LeChauncy D. , Akeroyd Julia M. , Ramsey David J. , Ballantyne Christie M. , Petersen Laura A. 
Published: October 2014

ABSTRACTBackgroundThe recent cholesterol guideline recommends high‐intensity statins in cardiovascular disease (CVD) patients. High‐intensity statins are associated with more frequent side effects. Therefore, it may be of concern that these recommendations might reduce statin adherence.HypothesisHigh‐intensity statins are associated with lower adherence compared with low‐ to moderate‐intensity statins.MethodsIn a national database of 972 532 CVD patients from the Veterans Health Administration, we identified patients receiving statins between October 1, 2010, and September 30, 2011. We assessed statin adherence by calculating proportion of days covered (PDC) and determined whether high‐intensity statin therapy was independently associated with a lower PDC.ResultsStatins were prescribed in 629 005 (64.7%). Of those, 229 437 (36.5%) received high‐intensity statins. Mean PDC (0.87 vs 0.86, P < 0.0001) and patients with PDC ≥0.80 (76.3% vs 74.2%, P < 0.0001) were slightly higher for those receiving low‐ to moderate‐intensity compared with high‐intensity statins. In adjusted analyses, high‐intensity statin use was associated with a significant but modest PDC reduction compared with low‐ to moderate‐intensity statin use, whether PDC was assessed as a continuous (β‐coefficient: −0.008, P < 0.0001) or categorical (PDC ≥0.80 [odds ratio: 0.94, 95% confidence interval: 0.93‐0.96]) measure of statin adherence.ConclusionsAn approach of high‐intensity statin therapy will lead to a significant practice change, as the majority of CVD patients are not on high‐intensity therapy. However, this change may be associated with a very modest reduction in statin adherence compared with low‐ to moderate‐intensity therapy that is unlikely to be of clinical significance.
Variations in Growth, Clonal and Sexual Reproduction of Spartina alterniflora Responding to Changes in Clonal Integration and Sand Burial
Authors: Xiao Yan , Zhao Hui , Yang Wen , Qing Hua , Zhou Changfang , Tang Junbing , An Shuqing 
Published: October 2014

AbstractClonal plants can shift their allocation to growth, clonal, and sexual reproduction under different conditions. To test this hypothesis, a greenhouse experiment was conducted to explore the effects of sand burial degrees and clonal integration on the trade‐offs among growth, clonal, and sexual reproduction in an invasive species, Spartina alterniflora. Ramets of connected genets to artificially disconnected ramets buried by sand to a depth of 0, 8, and 16 cm, respectively, were compared. Clonal integration stimulated the growth and clonal reproduction of daughter ramets, but has negative effects on these performances of mother ramets. Consequently, clonal integration had no effect on the clones. Biomass allocation to sexual reproduction in mother ramets and whole clones were stimulated by severing rhizomes. It could be concluded that the increased performances of daughter ramets occurred when mother ramets showed decreases of growth, clonal, and sexual reproduction when buried. Increased sexual reproduction in response to sand burial might represent a compensatory mechanism to reduced growth and clonal reproduction in S. alterniflora. Rhizome fragmentation did not influence growth and clonal reproduction, but increased sexual reproduction at the clone level.
Polycyclic Aromatic Hydrocarbons in the Food Web of Coastal Wetlands: Distribution, Sources and Potential Toxicity
Authors: Zhang Yu , Cui Baoshan , Zhang Qijun , Liu Xinhui 
Published: October 2014

AbstractTo elucidate the distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in coastal wetlands and determine the potential toxicity of PAHs to the food web, we analyzed the concentrations of 16 PAHs in the water, sediments, primary producer, invertebrates, fishes, and birds of the coastal wetlands of the Yellow River Delta. The trophic level of the food web was described using the stable carbon isotopes (δ15C) and nitrogen isotopes (δ15N) in organisms. The sources of the PAHs were evaluated with characteristic ratio methods, and their potential toxicity was analyzed in accordance with toxicity equivalency factors. Results showed that the sediments contain higher amounts of PAHs than does the water. The amount of PAHs in the food web follows the order birds > fishes > invertebrates > primary producer. The amount of PAHs in the organs of birds follows the order kidney > lung > heart > liver > muscle. The PAHs concentration in migratory birds, namely, Ardea purpurea, Larus saundersi, Egretta garzetta, and Cygnus cygnus is higher than that in the resident bird Anas poecilorhyncha. The Yellow River Delta is contaminated to a lesser extent than the other wetlands. The PAHs in the coastal wetlands of the Yellow River Delta originate primarily from a mixture of petroleum and combustion sources. The potential toxicity of these PAHs is of moderate or low level. Thus, reducing the release of PAHs through petroleum and combustion sources is necessary to strengthen the protection of plants and animals in the food web of coastal wetlands.
Stimuli‐Responsive Polymeric Nanoparticles for Nanomedicine
Authors: Crucho Carina I. C. 
Published: October 2014

AbstractNature continues to be the ultimate in nanotechnology, where polymeric nanometer‐scale architectures play a central role in biological systems. Inspired by the way nature forms functional supramolecular assemblies, researchers are trying to make nanostructures and to incorporate these into macrostructures as nature does. Recent advances and progress in nanoscience have demonstrated the great potential that nanomaterials have for applications in healthcare. In the realm of drug delivery, nanomaterials have been used in vivo to protect the drug entity in the systemic circulation, ensuring reproducible absorption of bioactive molecules that do not naturally penetrate biological barriers, restricting drug access to specific target sites. Several building blocks have been used in the formulation of nanoparticles. Thus, stability, drug release, and targeting can be tailored by surface modification. Herein the state of the art of stimuli‐responsive polymeric nanoparticles are reviewed. Such systems are able to control drug release by reacting to naturally occurring or external applied stimuli. Special attention is paid to the design and nanoparticle formulation of these so‐called smart drug‐delivery systems. Future strategies for further developments of a promising controlled drug delivery responsive system are also outlined.
NaGdF4 Nanoparticles Coated with Functionalised Ethylenediaminetetraacetic Acid as Versatile Probes for Dual Optical and Magnetic Resonance Imaging
Authors: Carniato Fabio , Tei Lorenzo , Phadngam Suratchanee , Isidoro Ciro , Botta Mauro 
Published: October 2014

AbstractNaGdF4 nanoparticles (NPs) coated with organic ligands are known to provide efficient “positive” contrast in magnetic resonance imaging (MRI). Strongly chelating ligands, such as ethylenediaminetetraacetic acid (EDTA) and d,l‐1,2‐diaminopropionic‐N,N,N′,N′‐tetraacetic acid (EDTACOOH), which is an EDTA derivative with a functionalisable carboxylic group, were used to coat NaGdF4. The carboxylic group was used to insert a polyethylene glycol (PEG) functionality (to give EDTAPEG) to favour better suspension and stealth and/or a fluorescent dye to obtain dual optical/MRI probes. The relaxometric behaviour of these NPs was investigated as a function of the magnetic field strength, and a significant contribution from water molecules hydrogen bonded to the organic coating was evidenced. The chemical stability of the NPs was evaluated both in a physiological medium and in the presence of a strong chelating agent. Finally, the dye‐functionalised NPs were tested in ovarian carcinoma cells as dual optical and MRI probes.
Synthesis of NiGa2O4 Octahedron Nanocrystal with Exposed {111} Facets and Enhanced Efficiency of Photocatalytic Water Splitting
Authors: Zhou Shi‐Xiong , Lv Xiao‐Jun , Zhang Chen , Huang Xing , Kang Lei , Lin Zhe‐shuai , Chen Yong , Fu Wen‐Fu 
Published: October 2014

AbstractFor the first time, octahedral NiGa2O4 nanocrystals having reactive pH‐dependent {111} facets are synthesized through a facile hydrothermal route without using any template or organic surfactant. The {111} facets of octahedral NiGa2O4 display clearly enhanced photocatalytic generation of hydrogen and oxygen from water splitting and good photocatalytic stability. Density functional calculations suggest that mixed statistically occupied Ga/Ni (fourfold‐ and sixfold‐coordinated Ga/Ni) are most likely to be exposed at the (111) surface of NiGa2O4, which is very favorable for enhancing the photocatalytic activities, and the photoelectrochemical properties show that the NiGa2O4 octahedron displays a better photocurrent than NiGa2O4 nanorods with the [100] growth direction. The transient photocurrent decay scan results demonstrate that the NiGa2O4 octahedron exposed {111} facet electrode exhibits a transient decay time of 4 s, whereas this time is only 2 s for NiGa2O4 nanorod electrodes with the [100] growth direction. This longer transient decay time indicates that the charge‐carrier recombination rate is lower in the NiGa2O4 octahedron electrode, which will contribute to the enhancement of the photocatalytic activity. The present study also demonstrates that designing nanostructures with the appropriate morphology and surface structures is a feasible approach for enhancing the photoexcited charge‐transfer lifetime and developing highly active semiconductor photocatalysts.
Client Attachment Status and Changes in Therapeutic Alliance Early in Treatment
Authors: Siefert Caleb J. , Hilsenroth Mark J. 
Published: October 2014

Several studies have examined associations between client attachment status and therapeutic alliance. Most, however, measure alliance at a single time point only. This study is among the first to examine how client attachment relates to changes in the therapeutic alliance early in treatment. Forty‐six outpatients from a university‐based community clinic participated. Attachment status was assessed with the Relationship Questionnaire (Bartholomew & Horowitz, 1991) prior to beginning treatment. Participants rated therapeutic alliance after an evaluation feedback session and again early in psychotherapy. Fearful insecurity was associated with declines in therapeutic alliance, while attachment security was associated with increasing client–therapist bonds. Although unrelated to global alliance, preoccupied insecurity was associated with greater confident collaboration at both time points and declines in idealized relationship from the evaluation to the early therapy time point. Results are discussed in light of prior theoretical formulations and previous research. Limitations of the study are reviewed, implications for clinical practice are noted, and suggestions for future research are made. Copyright © 2014 John Wiley & Sons, Ltd.Key Practitioner Message

Assessing client attachment status can provide clinicians with information that helps them identify clients at risk for difficulties establishing a therapeutic alliance.
Clients high in attachment security are more likely to develop strong bonds with therapists during the early portion of treatment.
Clients high in fearful insecurity are at risk for developing weaker alliances early in treatment. Such clients appear more likely to experience declines in client–therapist bond, goal‐task agreement and overall alliance early in the treatment process.
Clients high in preoccupied insecurity may enter therapy with great confidence in the therapist and willing to engage in therapy but report more conflicts with therapists in the early phase of treatment.
Formation of a CdO Layer on CdS/ZnO Nanorod Arrays to Enhance their Photoelectrochemical Performance
Authors: Van Thanh Khue , Pham Long Quoc , Kim Do Yoon , Zheng Jin You , Kim Dokyoung , Pawar Amol U. , Kang Young Soo 
Published: October 2014

AbstractThe performance and photocatalytic activity of the well‐known CdS/ZnO nanorod array system were improved significantly by the layer‐by‐layer heterojunction structure fabrication of a transparent conductive oxide (TCO) CdO layer on the CdS/ZnO nanorods. Accordingly, a CdO layer with a thickness of approximately 5–10 nm can be formed that surrounds the CdS/ZnO nanorod arrays after annealing at 500 °C under air. At an external potential of 0.0 V vs. Ag/AgCl, the CdO/CdS/ZnO nanorod array electrodes exhibit an increased incident photon to conversion efficiency, which is significantly higher than that of the CdS/ZnO nanorod array electrodes. The high charge separation between the electrons and holes at the interfaces of the heterojunction structure results from the specific band energy structure of the photoanode materials, and the unique high conductivity of the CdO layer is attributed to the suppression of electron–hole recombination; this suppression enhances the photocurrent density of the CdO/CdS/ZnO nanorod arrays. The photoresponse of the electrodes in an electrolytic solution without sacrificial agents indicated that the CdO layer also has the ability to suppress the well‐known photocorrosive behavior of CdS/ZnO nanorods.
Sulfur‐Doped Carbons Prepared from Eutectic Mixtures Containing Hydroxymethylthiophene as Metal‐Free Oxygen Reduction Catalysts
Authors: López‐Salas Nieves , del Monte Francisco , Tamayo Aitana , Fierro José Luís G. , De Lacey Antonio L. , Ferrer M. Luisa , Gutiérrez María C. 
Published: October 2014

AbstractA template‐free approach based on the use of eutectic mixtures composed of 2‐hydroxymethylthiophene and furfuryl alcohol has been designed for the preparation of hierarchical sulfur‐doped carbons (SPCs) in monolithic form. The temperature used for carbonization, for example, 600, 800, or 900 °C, determined most of the physicochemical properties of the resulting SPCs. Thus, the surface area increased from below 400 to up 775 m2 g−1, along with the carbonization temperature, whereas the sulfur content decreased from approximately 15 to 5 wt %. The oxygen reduction reaction performance in samples carbonized at 900 °C was good, with the four‐electron‐transfer reaction prevailing over the two‐electron‐transfer one. Interestingly, the methanol tolerance and stability of these SPCs were also remarkable, with less than 5 % current decrease immediately after methanol addition, whereas, in terms of stability, the current decrease was below 8 % after 20000 s. This performance was in the range of that found not only for other SPCs, but also for many nitrogen‐doped and even some dual‐doped (S and N) ones.
Automating the sizing of transistors in CMOS gates for low‐power and high‐noise margin operation
Authors: Beg Azam 
Published: October 2014

SummaryThis paper presents an automatic method for sizing the transistors in CMOS gates. The method utilizes a feedback control system to efficiently optimize the transistor sizes in small and large fan‐in gates, with the primary goal of enhancing noise robustness (as characterized by the static noise margin). The gates retain their robustness under threshold‐voltage variations over a range of supply voltages. The optimized gates not only expend reduced power and energy, but also take up less area than the conventional ones. These multi‐faceted gains, however, do incur some performance loss. Copyright © 2014 John Wiley & Sons, Ltd.
Optokinetic stimulation increases limb pain and forehead hyperalgesia in complex regional pain syndrome
Authors: Knudsen L.F. , Drummond P.D. 
Published: October 2014

AbstractBackgroundAmbiguous visual stimuli increase limb pain in patients with complex regional pain syndrome (CRPS), possibly due to afferent sensory feedback conflicts. Conflicting sensory stimuli can also generate unpleasant sensations in healthy people such as during motion sickness. We wanted to investigate the mechanisms underlying the link between sensory conflicts and pain in CRPS using optokinetic stimulation (OKS) – a method known to induce motion sickness.MethodsTwenty‐one CRPS patients underwent OKS and rated symptoms of motion sickness. Patients also rated limb pain and pain‐related distress before, during and after OKS. In addition, pressure‐pain and sharpness sensations were investigated on both sides of the forehead and in the affected and contralateral limb before and after OKS.ResultsLimb pain and forehead hyperalgesia to pressure increased in parallel in response to OKS. In a subgroup of nauseated patients who withdrew early from OKS, hyperalgesia to pressure in the ipsilateral forehead persisted longer than in the remaining participants. Sharpness sensations remained constant at all sites.ConclusionsSensory conflicts may facilitate pain in CRPS by activating the mechanisms of general facilitation of nociception and, during more severe sensory conflicts, also a facilitatory mechanism that operates mainly ipsilateral to the affected limb.