bluuebunny/crossref_metadata_2025 huggingface dataset:
Entanglements in P3HT and their influence on thin‐film mechanical properties: Insights from molecular dynamics simulations
Authors: Tummala Naga Rajesh , Risko Chad , Bruner Christopher , Dauskardt Reinhold H. , Brédas Jean‐Luc
Published: April 2015

Due to their inherent mechanical flexibility and stretchability, organic‐based electronic devices have garnered a great deal of academic and industrial interest. Here, molecular‐dynamics simulations are used to examine the molecular‐scale details that govern the relationships among molecular weight, chain entanglement, persistence length, and the elastic characteristics of the widely studied π‐conjugated polymer poly‐(3‐hexyl thiophene), P3HT. Oligomers containing at least 50 monomer units are required in the simulations to observe elastic behavior in P3HT, while much longer chains are required to ensure description of appropriate levels of entanglement: only when the molecular weight is greater than 50 kDa, that is, oligomers with approximately 400 monomer units, is truly entangled behavior observed. Interestingly, results from primitive path analysis of amorphous P3HT matches well with the observed onsets of inter‐chain excitonic coherence with increased molecular weight. The simulations also indicate that the P3HT modulus saturates at 1.6 GPa for chain lengths of 50–100 monomers, a result that compares well with experimental results. This work highlights the care that needs to be taken to accurately model P3HT morphologies in relation to experimental measurements. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 934–942
Morphological and structural modifications of chemically‐prepared emeraldine polyaniline and zinc oxide in PAni‐ZnO composite
Authors: Vequizo Reynaldo M. , Bagsican Filchito Renee G. , Odarve Majvell Kay G.
Published: April 2015

In this paper, the characteristic changes on the surface morphology and structure of both emeraldine polyaniline (PAni) and ZnO films in the chemically‐prepared PAni‐ZnO composite are presented. The PAni‐ZnO composite on amorphous glass substrate was fabricated utilizing chemical bath deposition technique. The ZnO films were first synthesized using appropriate amounts of zinc sulphate and ammonium hydroxide. Emeraldine form polyaniline films were then grown on as‐prepared ZnO films using appropriate amounts of aniline hydrochloride and ammonium peroxydisulphate. The formation of zinc hydroxychloride hexagonal‐plate structures in the composite film resulted to morphological and structural modifications of PAni and ZnO composite films. The highly‐crystalline emeraldine polyaniline became amorphous when deposited as part of the composite while increased tensile strain was observed for ZnO in the composite due to stretching‐effect caused by zinc hydroxychloride along the outward‐planar direction. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Predicting the dynamics of social circles in ego networks using pattern analysis and GA K‐means clustering
Authors: Agarwal Vinti , Bharadwaj K. K.
Published: April 2015

The tremendous amount of content generated on online social networks has led to a radical paradigm shift in the interest of people to group friends dynamically and share content selectively. At large, social networking sites (e.g. Google+, Facebook, Twitter, etc.) offer users with various controls over categorizing their family members, friends, colleagues, etc. into one or more ‘circles’ that they want to share content with. However, it is typically impossible to design social circles in large networks and update their number and size, whenever networks grow. Aiming at predicting the dynamics of formation and evolution of social circles, we performed several experiments on ground‐truth data, and found that studying patterns of network and profile features at individual level rather than studying circle as a whole can greatly enhance the understanding of social circles development in online social networks. In this review, we first present a comprehensive study of the structural behavior of circles, and then build an observation that within every circle there exist some key elements, termed as ‘Node of Creations (NoCs)’, which play an important role in the development, survival, and evolvability of circle structures. We, therefore, propose a Genetic Algorithm–based framework to determine these key elements (NoCs) and differentiate Ego networks into non‐overlapping, hierarchically nested as well as overlapping circles by leveraging knowledge from the identified patterns in order to assist K‐means clustering. We have performed our experiments using Facebook and Twitter datasets and the experimental results clearly demonstrate the effectiveness of our scheme. WIREs Data Mining Knowl Discov 2015, 5:113–141. doi: 10.1002/widm.1150

This article is categorized under:

Technologies > Machine Learning

Technologies > Prediction

Technologies > Structure Discovery and Clustering
Protein–quantum dot nanohybrids for bioanalytical applications
Authors: Lee Jeong Yu , Kim Jee Seon , Park Jae Chul , Nam Yoon Sung
Published: April 2015

Quantum dots (QDs) coupled with biomolecules play an important role as optically and chemically stable bioimaging agents for various applications. These inorganic–biological hybrid conjugates have been demonstrated as powerful fluorescence tools for sensing, diagnostics, and labeling. This review focuses on protein–QD nanohybrids for different types of bioanalytical applications. There are various strategies to modify the surface properties of QDs to produce protein–QD nanohybrids that are stable in biological fluids. We expect that multifunctional protein–QD nanohybrids can be used as a powerful optical probe for various biological applications. WIREs Nanomed Nanobiotechnol 2016, 8:178–190. doi: 10.1002/wnan.1345

This article is categorized under:

Diagnostic Tools > Biosensing

Diagnostic Tools > Diagnostic Nanodevices

Diagnostic Tools > In Vitro Nanoparticle-Based Sensing
Smoothed Particle Hydrodynamics – partikelbasierte Strömungsberechnung zur Anwendung in der Siedlungswasserwirtschaft
Authors: Meister Michael , Fleischhacker Nikolaus , Rauch Wolfgang
Published: April 2015

Zahlreiche Strömungsprobleme in der Siedlungswasserwirtschaft können mittels vereinfachter Methoden berechnet werden. Zum Beispiel werden Reaktoren meist als voll durchmischt angenommen und Gerinneströmungen durch ein eindimensionales Modell approximiert. Beeinflusst aber die Strömung die Funktion der Infrastruktur, ist es notwendig, komplexere numerische Berechnungen mit Computational-Fluid-Dynamics-Methoden durchzuführen. Beispiele dafür sind die Modellierung von Absetzbecken, Faulbehältern und komplexen Mischwasserbehandlungsanlagen. Numerische Strömungsberechnungen in der Siedlungswasserwirtschaft verwenden bislang gitterbasierte Computational-Fluid-Dynamics-Methoden. In diesem Artikel wird anhand von Beispielen die Anwendungsmöglichkeit einer alternativen partikelbasierten Methode, nämlich von Smoothed Particle Hydrodynamics, diskutiert.
Pilot studies on scale-up biocatalysis of 7-β-xylosyl-10-deacetyltaxol and its analogues by an engineered yeast
Authors: Liu Wan-Cang , Zhu Ping
Published: April 2015

Paclitaxel content in yew tree is extremely low, causing a worldwide shortage of this important anticancer drug. Yew tree can also produce abundant 7-β-xylosyl-10-deacetyltaxol that can be bio-converted into 10-deacetyltaxol for semi-synthesis of paclitaxel. However, the bio-conversion by the screened natural microorganisms was inefficient. We have constructed the recombinant yeast with a glycoside hydrolase gene from Lentinula edodes and explored the bioconversion. Based on previously established reaction conditions, the bioconversion of 7-β-xylosyl-10-deacetyltaxol or its extract was further optimized and scaled up with the engineered yeast harvested from 200-L scale high-cell-density fermentation. The optimization included the freeze-dried cell amount, dimethyl sulfoxide concentration, addition of 0.5 % antifoam supplement, and substrate concentration. A 93–95 % bioconversion and 83 % bioconversion of 10 and 15 g/L 7-β-xylosyltaxanes in 10 L reaction volume were achieved, respectively. The yield of 10-deacetyltaxol reached 10.58 g/L in 1 L volume with 15 g/L 7-β-xylosyl-10-deacetyltaxol. The conversion efficiencies were not only much higher than those of other reports and our previous work, but also realized in 10 L reaction volume. A pilot-scale product purification was also established. Our study bridges the gap between the basic research and commercial utilization of 7-β-xylosyl-10-deacetyltaxol for the industrial production of semi-synthetic paclitaxel.
The Effects of Social Capital and Neighborhood Characteristics on Intimate Partner Violence: A Consideration of Social Resources and Risks
Authors: Kirst Maritt , Lazgare Luis Palma , Zhang Yu Janice , O’Campo Patricia
Published: April 2015

Intimate partner violence (IPV) is a growing public health problem, and gaps exist in knowledge with respect to appropriate prevention and treatment strategies. A growing body of research evidence suggests that beyond individual factors (e.g., socio‐economic status, psychological processes, substance abuse problems), neighborhood characteristics, such as neighborhood economic disadvantage, high crime rates, high unemployment and social disorder, are associated with increased risk for IPV. However, existing research in this area has focused primarily on risk factors inherent in neighborhoods, and has failed to adequately examine resources within social networks and neighborhoods that may buffer or prevent the occurrence of IPV. This study examines the effects of neighborhood characteristics, such as economic disadvantage and disorder, and individual and neighborhood resources, such as social capital, on IPV among a representative sample of 2412 residents of Toronto, Ontario, Canada. Using a population based sample of 2412 randomly selected Toronto adults with comprehensive neighborhood level data on a broad set of characteristics, we conducted multi‐level modeling to examine the effects of individual‐ and neighborhood‐level effects on IPV outcomes. We also examined protective factors through a comprehensive operationalization of the concept of social capital, involving neighborhood collective efficacy, community group participation, social network structure and social support. Findings show that residents who were involved in one or more community groups in the last 12 months and had high perceived neighborhood problems were more likely to have experienced physical IPV. Residents who had high perceived social support and low perceived neighborhood problems were less likely to experience non‐physical IPV. These relationships did not differ by neighborhood income or gender. Findings suggest interesting contextual effects of social capital on IPV. Consistent with previous research, higher levels of perceived neighborhood problems can reflect disadvantaged environments that are more challenged in promoting health and regulating disorder, and can create stressors in which IPV is more likely to occur. Such analyses will be helpful to further understanding of the complex, multi‐level pathways related to IPV and to inform the development of effective programs and policies with which to address and prevent this serious public health issue.
1H‐MRS in glutaric aciduria type 1: impact of biochemical phenotype and age on the cerebral accumulation of neurotoxic metabolites
Authors: Harting Inga , Boy Nikolas , Heringer Jana , Seitz Angelika , Bendszus Martin , Pouwels Petra J.W. , Kölker Stefan
Published: April 2015

Background

In glutaric aciduria type 1 (GA1) the neurotoxic metabolites glutaric acid (GA) and 3‐hydroxyglutaric acid (3‐OH‐GA) accumulate within the brain. Due to limited efflux across the blood–brain‐barrier biochemical monitoring of intracerebrally accumulating toxic metabolites is as yet not possible.

Aims

To investigate brain metabolic patterns in glutaric aciduria type 1 using 1H magnetic resonance spectroscopy (1H‐MRS) with focus on detecting the disease‐related neurotoxic metabolites GA and 3‐OH‐GA.

Patients and methods

Short echo time 1H‐MRS was performed in 13 treated metabolically stable patients. Twenty‐one white matter and 16 basal ganglia spectra from 12 patients (age range 7 months – 22 years) were included. Subgroups based on age, biochemical phenotype and/or associated MRI changes were compared with control spectra.

Results

GA was elevated in white matter of patients. 3‐OH‐GA was elevated in white matter of older patients with associated signal changes on MRI, which was structurally characterized by decreased creatine and phosphocreatine (tCr) and elevated choline (Cho). Metabolite changes differed with biochemical phenotype and disease duration: Low excretors with up to 30 % residual enzyme activity had only mildly, non‐significantly elevated GA and mildly subnormal N‐acetylaspartate (tNAA). High excretors with complete lack of enzyme activity had significantly increased GA, tNAA was mildly subnormal in younger and decreased in older high excretors.

Conclusions

GA and 3‐OH‐GA are detectable by in vivo 1H‐MRS, which might finally allow biochemical follow‐up monitoring of intracerebrally accumulating neurotoxic metabolites in GA1. A high excreting phenotype appears to be a risk factor for cerebral GA accumulation and progressive neuroaxonal compromise despite a similar clinical course in younger high and low excreting patients. This might have consequences for long‐term outcome.
A population‐based cohort study of stillbirth among twins in Lusaka, Zambia
Authors: Stringer Elizabeth M. , Chibwesha Carla , Stoner Marie , Vwalika Bellington , Joseph Jessica , Chi Benjamin H. , Kaunda Eugene , Goodnight William , Stringer Jeffrey S.A.
Published: April 2015

Objective

To determine rates of stillbirth and the associated risk factors for stillbirth among twins delivered in Lusaka, Zambia.

Methods

A retrospective cohort analysis was conducted of singletons and twins delivered at 26 public sector facilities between February 1, 2006, and May 31, 2013. Data were obtained from the Zambian Electronic Perinatal Record System. Risk of stillbirth was estimated using logistic regression.

Results

Overall, 260 657 singletons and 4021 twin pairs were included. There were 5105 stillbirths; 317 twins were stillborn. The crude stillbirth rate for twins was 39.4 per 1000 births (95% confidence interval [CI] 35.2–43.7) whereas the rate for singletons was 18.4 per 1000 births (95% CI 17.9–18.9; P < 0.001). Factors associated with stillbirth among twins were increased interval between delivery (> 60 minutes), low birth weight (< 2500 g), birth order (being the second‐born), and difference in birth weights (> 30% discordance).

Conclusion

Twins were at an increased risk of stillbirth. Improved understanding of factors associated with stillbirth in this population could help to improve perinatal outcomes globally.
MORAL CLUMSINESS
Authors: Arango Alejandro
Published: April 2015

What would happen if one morning you wake up clumsy, as if your sense of touch were unreliable, arbitrarily on and off? And what would this clumsiness look like if we could transfer it to the moral sense? The article expounds an interesting analogy between the sense of touch, loosely construed, and the moral sense: just as a sort of consistency is necessary for the sense of touch to do its job, so it is for the moral sense to play its part. Touch enables us to navigate the everyday world of coffee pots and staircases; our moral sensibility comes into play when we act or when we judge our actions and those of others, and plays a directive role in what we feel, how we feel it, and how we react to it. Taking the analogy further, I will suggest that inconsistency causes, in both cases, a certain clumsiness, and that clumsiness is linked to arbitrariness – like the person that helps others in dire need, but only does so on some rainy days.
ON INTROSPECTION AND INTROSPECTIONISM
Authors: Beenfeldt Christian
Published: April 2015

For some time now, the topics of introspection, inner experience and so-called first-person approaches to the mental, have been the subject of attention in philosophy, psychology and consciousness studies. Indeed, some philosophers (such as David Chalmers) think that a central task of the latter field is to systematically relate and integrate data about subjective experience (first-person data) and data about behavior and brain processes (third-person data).
THE RATIONALITY OF RELIGIOUS BELIEFS
Authors: Frances Bryan
Published: April 2015

Many highly educated people think religious belief is irrational and unscientific. If you ask a philosopher, however, you'll likely get two answers: most religious belief is rational in some respects and irrational in other respects. In this essay I explain why they think religious belief is rational. In a sequel essay I explain why they think the very same beliefs are irrational.
THE IMMORALITY OF PRAYER
Authors: Lyon Ardon
Published: April 2015

It's no surprise that one shouldn't pray for bad things to happen, for it's always wicked to attempt to bring about evil. But perhaps surprisingly one shouldn't pray for good things either. For if there is an Omnipotent, Omniscient and Omni-Benevolent Deity who intervenes at all in the workings of the world, then He will do whatever is best anyway, and if you pray for what He wouldn't otherwise have done then it must, perhaps unknown to you, be wrong. If there is no God then He will not answer your prayers, although they might be efficacious in other ways.
A PLATONIC METHOD FOR MAKING IDEAS ENGAGING AND ACCESSIBLE
Authors: More Charles
Published: April 2015

In this essay, I introduce an imaginative method for transforming reasoned arguments of specialists into a form that is engaging and accessible to nonspecialists. I begin by reviewing a passage in Plato in which the method is used. I then develop an example of the method for a modern context. I conclude with reasons that philosophy ought to concern itself to engage the general public using imaginative methods of this kind.
A SIMPLIFIED ONTOLOGICAL ARGUMENT AND FICTIONAL ENTITIES
Authors: Di Muzio Gianluca
Published: April 2015

This paper shows that a recent, simplified version of St. Anselm's proof of the existence of God has its flank open to Gaunilo's ‘Lost Island’ objection. Reformulating Anselm's line of reasoning in terms of the distinction between mediated and unmediated causal powers, as the simplified proof does, makes it harder for Anselm's supporters to refute the objection that the ontological argument absurdly entails the existence of all kinds of fictional entities.
Particle Accelerator in Space Could Help Scientists Study Auroras
Authors: Zastrow Mark
Published: April 2015

Researchers could launch an electron beam device into space to study the Earth's magnetic field and trigger artificial auroras and lightning.
Plasmonic eigenmodes in individual and bow-tie graphene nanotriangles
Authors: Wang Weihua , Christensen Thomas , Jauho Antti-Pekka , Thygesen Kristian S. , Wubs Martijn , Mortensen N. Asger
Published: April 2015

In classical electrodynamics, nanostructured graphene is commonly modeled by the computationally demanding problem of a three-dimensional conducting film of atomic-scale thickness. Here, we propose an efficient alternative two-dimensional electrostatic approach where all calculation procedures are restricted to the graphene sheet. Furthermore, to explore possible quantum effects, we perform tight-binding calculations, adopting a random-phase approximation. We investigate multiple plasmon modes in 20 nm equilateral triangles of graphene, treating the optical response classically as well as quantum mechanically. Compared to the classical plasmonic spectrum which is “blind” to the edge termination, we find that the quantum plasmon frequencies exhibit blueshifts in the case of armchair edge termination of the underlying atomic lattice, while redshifts are found for zigzag edges. Furthermore, we find spectral features in the zigzag case which are associated with electronic edge states not present for armchair termination. Merging pairs of triangles into dimers, plasmon hybridization leads to energy splitting that appears strongest in classical calculations while splitting is lower for armchair edges and even more reduced for zigzag edges. Our various results illustrate a surprising phenomenon: Even 20 nm large graphene structures clearly exhibit quantum plasmonic features due to atomic-scale details in the edge termination.
Bare magnetic nanoparticles as fluorescence quenchers for detection of thrombin
Authors: Yu Jiemiao , Yang Liangrong , Liang Xiangfeng , Dong Tingting , Liu Huizhou
Published: April 2015

Bare magnetic nanoparticles as fluorescence quenchers and an aptamer as an affinity ligand were used to detect thrombin, and this is a simple and sensitive assay.
Catalyst-controlled reverse selectivity in C–C bond formation: NHC-Cu-catalyzed α-selective allylic alkylation with organolithium reagents
Authors: Pizzolato Stefano F. , Giannerini Massimo , Bos Pieter H. , Fañanás-Mastral Martín , Feringa Ben L.
Published: April 2015

An efficient and highly α-selective copper-catalyzed allylic alkylation of allylic halides with organolithium reagents is presented.
Surface electrochemistry of CO2reduction and CO oxidation on Sm-doped CeO2−x: coupling between Ce3+and carbonate adsorbates
Authors: Feng Zhuoluo A. , Machala Michael L. , Chueh William C.
Published: April 2015

Strong coupling between carbonate coverage, surface Ce3+concentration and overpotential reveals rate-limiting step in CO oxidation and CO2reduction.
Collision-induced dissociation products of the protonated dipeptide carnosine: structural elucidation, fragmentation pathways and potential energy surface analysis
Authors: Moustafa Eslam M. , Ritacco Ida , Sicilia Emilia , Russo Nino , Shoeib Tamer
Published: April 2015

CID experiments on protonated carnosine, [carnosine + H]+, employing several collision energies were shown to yield eleven different fragment ions, with the production of [carnosine–H2O + H]+ and [carnosine–NH3 + H]+ being the lowest energy processes.
Surface enhanced resonance Raman detection of a catalytic intermediate of DyP-type peroxidase
Authors: Todorovic Smilja , Hildebrandt Peter , Martins Lígia O.
Published: April 2015

We report herein the vibrational spectroscopic characterisation of a catalytic intermediate formed by the reaction of H2O2with DyP-type peroxidase immobilised on a biocompatible coated metal support.
The correlation of the binding mechanism of the polypyrrole–carbon capacitive interphase with electrochemical stability of the composite electrode
Authors: Mosch Heike L. K. S. , Höppener Stephanie , Paulus Renzo M. , Schröter Bernd , Schubert Ulrich S. , Ignaszak Anna
Published: April 2015

Carbon–polymer composites for organic batteries, capacitors, capacitive water desalination reactors and electrochemical sensors.
The Soret absorption band of isolated chlorophyll a and b tagged with quaternary ammonium ions
Authors: Stockett Mark H. , Musbat Lihi , Kjær Christina , Houmøller Jørgen , Toker Yoni , Rubio Angel , Milne Bruce F. , Brøndsted Nielsen Steen
Published: April 2015

The true colors of chlorophyll a and b, isolated in vacuo, are revealed from a combination of gas-phase ion spectroscopy and TD-DFT calculations.
Silica-nanosphere-based organic–inorganic hybrid nanomaterials: synthesis, functionalization and applications in catalysis
Authors: Sharma R. K. , Sharma Shivani , Dutta Sriparna , Zboril Radek , Gawande Manoj B.
Published: April 2015

Fabrication of silica nanosphere based organic–inorganic hybrid materials and their applications in the field of catalysis.
3,4-Diamino-1,2,4-triazole based energetic salts: synthesis, characterization, and energetic properties
Authors: Wu Jin-Ting , Zhang Jian-Guo , Yin Xin , Cheng Zi-Yuan , Xu Cai-Xia
Published: April 2015

A series of energetic salts based on 3,4-diamino-1,2,4-triazole with promising detonation performances have been synthesized using a metathesis reaction method or a protonation reaction method.
The effect of manganese in a CdS/PbS colloidal quantum dot sensitized TiO2 solar cell to enhance its efficiency
Authors: Kim Hee-Je , Lee Hyun-Dong , Pavan Kumar Challa Shesha Sai , Rao Sunkara Srinivasa , Chung Sang-Hwa , Punnoose Dinah
Published: April 2015

The PbS/Mn-CdS electrode shows superior stability in a sulfide/polysulfide electrolyte with a power conversion efficiency (η) of 3.55%.
CuBr2-catalyzed enantioselective routes to highly functionalized and naturally occurring allenes
Authors: Tang Xinjun , Huang Xin , Cao Tao , Han Yulin , Jiang Xingguo , Lin Weilong , Tang Yang , Zhang Jiasheng , Yu Qiong , Fu Chunling , Ma Shengming
Published: April 2015

CuBr2-catalyzed highly enantioselective synthesis of functionalized 1,3-disubstituted allenes including three natural ones from readily available terminal alkynes, aldehydes, and (S)-α,α-diphenylprolinol has been demonstrated.
Reversible chain transfer catalyzed polymerization (RTCP) in nitrogen-based solvents without additional catalysts
Authors: Bai Liangjiu , Wang Wenxiang , Chen Hou , Wang Minghua , Cheng Zhenping
Published: April 2015

N,N-Dimethylformamide (DMF) andN-methyl-2-pyrrolidone (NMP) as typical nitrogen-based solvents were used as the catalyst for RTCP without additional catalyst, which could also be carried out in the presence of a limited amount of air.
In situ growth of metallic silver on glucose oxidase for a highly sensitive glucose sensor
Authors: Sun Qiang-Qiang , Yu Ya-Nan , Li Jin-Jin , Bao Shu-Juan
Published: April 2015

A bio-composite was assembled by in situ reducing Ag+ to Ag in glucose oxidase solution and used to detect glucose.
Nickel ion coupled counter complexation and decomplexation through a modified supported liquid membrane system
Authors: Talebi Amir , Teng Tjoon Tow , Alkarkhi Abbas F. M. , Ismail Norli
Published: April 2015

Complexation and decomplexation stoichiometry between nickel and D2EHPA in an SLM system are determined, confirmed by Job’s method and loading test.
Effect of a silica nanofiller on the structure, dynamics and thermostability of LDPE in LDPE/silica nanocomposites
Authors: Olmos Dania , González-Gaitano Gustavo , González-Benito Javier
Published: April 2015

Study of molecular interactions and dynamics in LDPE–silica nanocomposites using FTIR spectroscopy.
Nanostructural morphology master-regulated the cell capture efficiency of multivalent aptamers
Authors: Xie Liping , Cheng Hao , Qi Hao , Wang Tongzhou , Zhao Hui , Huang Guoliang , Du Yanan
Published: April 2015

The nanostructural features of stretched multivalent aptamers significantly improve the cell enrichment efficiency to about 16 fold higher than normal multivalent aptamers.
Synthesis and optical properties of gold nanoparticle networks cross-linked with chain-length-controlled polymers
Authors: Sugata Emi , Kobatake Seiya
Published: April 2015

We synthesized gold nanoparticle networks by a cross-linking of gold nanoparticles with chain-length-controlled polymers having SH groups at both termini.
Discovery of 3-O-β-chacotriosyl oleanane-type triterpenes as H5N1 entry inhibitors
Authors: Song Gaopeng , Shen Xintian , Li Sumei , Si Hongzong , Li Yibin , Luan Haiye , Fan Jihong , Liang Qianqian , Liu Shuwen
Published: April 2015

3-O-β-Chacotriosyl GA–Me5was discovered as a novel H5N1 entry inhibitor.
Gold immobilized onto poly(ionic liquid) functionalized magnetic nanoparticles: a robust magnetically recoverable catalyst for the synthesis of propargylamine in water
Authors: Moghaddam Firouz Matloubi , Ayati Seyed Ebrahim , Hosseini Seyed Hassan , Pourjavadi Ali
Published: April 2015

Supported gold(iii) on poly(ionic liquid) coated on magnetic nanoparticles produced a highly active, stable, recoverable and high loading for the synthesis of propargylamines (A3 coupling reaction) under green conditions.
Homostructured negative differential resistance device based on zigzag phosphorene nanoribbons
Authors: Zhang Chenhui , Xiang Gang , Lan Mu , Tang Zhijie , Deng Lidong , Zhang Xi
Published: April 2015

Robust negative differential resistance as well as quite large currents are observed in zigzag phosphorene nanoribbon homostructures.
A microfluidic approach to study the effect of bacterial interactions on antimicrobial susceptibility in polymicrobial cultures
Authors: Mohan Ritika , Sanpitakseree Chotitath , Desai Amit V. , Sevgen Selami E. , Schroeder Charles M. , Kenis Paul J. A.
Published: April 2015

An easy-to-use, lab-on-a-chip platform to rapidly quantify the efficacy of antibiotics to treat polymicrobial infections.
Roll-coating fabrication of ITO-free flexible solar cells based on a non-fullerene small molecule acceptor
Authors: Liu Wenqing , Shi Hangqi , Andersen Thomas R. , Zawacka Natalia K. , Cheng Pei , Bundgaard Eva , Shi Minmin , Zhan Xiaowei , Krebs Frederik C. , Chen Hongzheng
Published: April 2015

Fully roll-coated ITO-free flexible organic solar cells based on a non-fullerene small molecule acceptor with a PCE of 0.65% were fabricated.
Heterogeneous flow kinematics of cellulose nanofibril suspensions under shear
Authors: Martoïa F. , Perge C. , Dumont P. J. J. , Orgéas L. , Fardin M. A. , Manneville S. , Belgacem M. N.
Published: April 2015

The coexistence of multiple flow bands, wall slippage and possible multidimensional effects in enzymatic and TEMPO cellulose nanofibril suspensions under shear were revealed using optical and ultrasonic speckle velocimetry (USV) rheometry techniques.
Amphiphilic fullerenes modified 1D ZnO arrayed nanorods–2D graphene hybrids as cathode buffer layers for inverted polymer solar cells
Authors: Hu Ting , Chen Lie , Deng Zhiqiang , Chen Yiwang
Published: April 2015

Amphiphilic fullerenes modified ZnO arrayed nanorods@RGO cathode buffer layer was developed to improve the performance of polymer solar cells.
Strategies for faster detachment of corneal cell sheet using micropatterned thermoresponsive matrices
Authors: Nara Sharda , Chameettachal Shibu , Midha Swati , Singh Himi , Tandon Radhika , Mohanty Sujata , Ghosh Sourabh
Published: April 2015

Direct write assembly of parallel patterns of gelatin–poly(N-isopropylacrylamide) hybrids serve as suitable thermoresponsive material to develop patterned cell sheets of functional keratocytes for constructing a bioequivalent of corneal stroma.
Depletion of the polyamines spermidine and spermine by overexpression of spermidine/spermine N1-acetyltransferase 1 (SAT1) leads to mitochondria-mediated apoptosis in mammalian cells
Authors: Mandal Swati , Mandal Ajeet , Park Myung Hee
Published: April 2015

The polyamines putrescine, spermidine and spermine are intimately involved in the regulation of cellular growth and viability. Transduction of human embryonic kidney (HEK) 293T cells with an adenovirus encoding a key polyamine catabolic enzyme, spermidine N1-acetyltransferase 1 (SSAT1)/SAT1 (AdSAT1), leads to a rapid depletion of spermidine and spermine, arrest in cell growth and a decline in cell viability. Annexin V/propidium iodide FACS analyses, terminal uridine nucleotide end-labelling (TUNEL) and caspase 3 assays showed a clear indication of apoptosis in AdSAT1-transduced cells (at 24–72 h), but not in cells transduced with GFP-encoding adenovirus (AdGFP). Apoptosis in the polyamine-depleted cells occurs by the mitochondrial intrinsic pathway, as evidenced by loss of mitochondrial membrane potential, increase in pro-apoptotic Bax, decrease in anti-apoptotic Bcl-xl, Bcl2 and Mcl-1 and release of cytochrome c from mitochondria, upon transduction with AdSAT1. Moreover, TEM images of AdSAT1-transduced cells revealed morphological changes commonly associated with apoptosis, including cell shrinkage, nuclear fragmentation, mitochondrial alteration, vacuolization and membrane blebbing. The apoptosis appears to result largely from depletion of the polyamines spermidine and spermine, as the polyamine analogues α-methylspermidine (α-MeSpd) and N1,N12-dimethylspermine (Me2Spm) that are not substrates for SAT1 could partially restore growth and prevent apoptosis of AdSAT1-transduced cells. Inhibition of polyamine oxidases did not restore the growth of AdSAT1-transduced cells or block apoptosis, suggesting that the growth arrest and apoptosis were not induced by oxidative stress resulting from accelerated polyamine catabolism. Taken together, these data provide strong evidence that the depletion of the polyamines spermidine and spermine leads to mitochondria-mediated apoptosis.
Total Syntheses of (–)-Alstolucines A, B, and F, (–)-Echitamidine, and (–)-N-Demethylalstogucine
Authors: Teijaro Christiana , Zhao Senzhi , Kokkonda Praveen , Andrade Rodrigo
Published: April 2015

The first enantioselective total syntheses of (–)-alstolucinces A, B, and F, (–)-echitamidine, and (–)-N-demethylalstogucine are reported. This article details the development of our first- and second-generation approaches toward the ABCE tetracyclic core of the strychnos alkaloids and the application thereof to the aforementioned targets. Key steps involve our sequential one-pot biscyclization method that constructs the C and E rings of the tetracyclic core and Rawal’s application of the intramolecular Heck reaction to secure the pentacyclic framework common amongst all targets.
Improvement in current efficiency of electroplated Fe-Ni films prepared in citric-acid-based baths
Authors: Watanabe Y. , Yanai T. , Otsubo M. , Takahashi A. , Ohgai T. , Nakano M. , Suzuki K. , Fukunaga H.
Published: April 2015

Fe-Ni films were electroplated in a citric-acid-based plating bath, focusing on the current efficiency of the plating process. We prepared the plating baths with various citric acid contents, and evaluated the magnetic properties of the films and the current efficiency. The film with Fe content of approximately 22 at. % was obtained by adjusting the iron sulfate content in the plating bath, and we found that the Fe-Ni films with low coercivity (<30 A/m) could be obtained in the baths with various citric acid contents. For the current efficiency, we found that the baths with low citric acid content are effective to obtain high efficiency. The bath with the citric acid content of 10 g/l showed high current efficiency (85%), and the high efficiency enables us to increase the plating rate. The maximum plating rate was 186 μm/h, and we obtained 1.3 times higher rate compared to that for our previous study. Therefore, we concluded that the bath with low citric acid content is a suitable plating bath to obtain thick Fe-Ni films in a short time.
Maxwell-Garnett effective medium theory: Quantum nonlocal effects
Authors: Moradi Afshin
Published: April 2015

We develop the Maxwell-Garnett theory for the effective medium approximation of composite materials with metallic nanoparticles by taking into account the quantum spatial dispersion effects in dielectric response of nanoparticles. We derive a quantum nonlocal generalization of the standard Maxwell-Garnett formula, by means the linearized quantum hydrodynamic theory in conjunction with the Poisson equation as well as the appropriate additional quantum boundary conditions.
Life, Death, and Resurrection: Accounting for State Uncertainty in Survival Estimation from Tagged Grass Carp
Authors: Stich Daniel S. , Jiao Yan , Murphy Brian R.
Published: April 2015

Information about Grass Carp Ctenopharyngodon idella survival would be useful for improving the management of fish used for aquatic weed control. Reliable methods for estimating annual poststocking survival of Grass Carp from radiotelemetry data do not exist because the fish remain sedentary for prolonged periods between movements, giving the false impression of death, only to be observed alive (i.e., “resurrected”) at a later date. We constructed a state-space, multistate mark–recapture survival model accounting for uncertainty in the live/dead states of tagged Grass Carp in a large (8,500 ha) reservoir, and we estimated monthly and annual survival. Model results were compared with life history-based methods for estimating survival, and survival estimates that were corrected for state misclassification were compared with uncorrected estimates. Corrected estimates of annual survival (mean = 0.23; 95% credible interval [CRI] = 0.15–0.41) contained less bias than uncorrected estimates (0.12; 95% CRI = 0.08–0.18). However, both corrected and uncorrected estimates were substantially lower than the survival expected based on life history theory (mean = 0.69; 95% confidence interval = 0.52–0.78), suggesting that mark–recapture survival estimates for Grass Carp might be negatively biased due to tag shedding, tag-related mortality, or both. Our model effectively reduced bias in monthly and annual survival estimates due to state misclassification, illustrating the potential for application of existing mark–recapture frameworks to estimate Grass Carp survival with telemetry data, despite the behavioral idiosyncrasies of the species. Furthermore, these methods may have application for studies of other animals that undergo periodic quiescence between movements, such as salmonids, ictalurids, and reef fishes. To account for bias resulting from tag loss, future mark–recapture studies of Grass Carp could incorporate tag shedding rates within the framework developed here.

Received July 19, 2014; accepted December 3, 2014
No Effects of Hyperosmolar Culture Medium on Tissue Regeneration by Human Degenerated Nucleus Pulposus Cells Despite Upregulation Extracellular Matrix Genes
Authors: Krouwels Anita , Popov-Celeketic Jelena , Plomp Saskia G.M. , Dhert Wouter J.A. , Öner F. Cumhur , Bank Ruud A. , Creemers Laura B.
Published: April 2015

Study Design.

An in vitro study using human degenerated nucleus pulposus cells.

Objective.

To determine the effect of osmolality and different osmolytes on the regeneration by human nucleus pulposus cells through gene expression and extracellular matrix production.

Summary of Background Data.

Intervertebral disc (IVD) degeneration is a major problem in developed countries. Regeneration of the IVD can prevent pain and costs due to diminished work absence and health care, and improve quality of life. The osmotic value of a disc decreases during degeneration due to loss of proteoglycans and might increase degeneration. It is known that gene expression of matrix genes of nucleus pulposus (NP) cells increases when cultured in hyperosmotic medium. Thus, increasing the osmolality of the disc might be beneficial for disc regeneration.

Methods.

In the current study, isolated degenerated human NP cells were used in regeneration culture with medium of different osmolalities, adjusted with different osmolytes. NaCl, urea and sucrose. The cells were cultured for 28 days and expression of matrix genes and production of glycosaminoglycans and collagen II were measured.

Results.

Gene expression for both collagen II and aggrecan increased with increasing osmolality using NaCl or sucrose, but not urea. Protein production however, was not affected by increasing osmolality and was decreased when using urea and sucrose. Expression of genes for Col1A1, MMP13, and MMP14 decreased with increasing osmolality, whereas expression of LOXL2 and LOXL3 increased. Transient expression of TonEBP was found 6 hours after the start of culture, but not at later time points.

Conclusion.

Although expression of matrix genes is upregulated, hyperosmolality does not enhance matrix production by nucleus pulposus cells. Raising osmolality can potentially increase matrix production, but in itself is not sufficient to accomplish regeneration in the current in vitro culture system.

Level of Evidence: N /A
Snap-through buckling of initially curved microbeam subject to an electrostatic force
Authors: Chen X. , Meguid S. A.
Published: April 2015

In this paper, the snap-through buckling of an initially curved microbeam subject to an electrostatic force, accounting for fringing field effect, is investigated. The general governing equations of the curved microbeam are developed using Euler–Bernoulli beam theory and used to develop a new criterion for the snap-through buckling of that beam. The size effect of the microbeam is accounted for using the modified couple stress theory, and intermolecular effects, such as van der Waals and Casimir forces, are also included in our snap-through formulations. The snap-through governing equations are solved using Galerkin decomposition of the deflection. The results of our work enable us to carefully characterize the snap-through behaviour of the initially curved microbeam. They further reveal the significant effect of the beam size, and to a much lesser extent, the effect of fringing field and intermolecular forces, upon the snap-through criterion for the curved beam.
Hybridization and pre-zygotic reproductive barriers inPlasmodium
Authors: Ramiro Ricardo S. , Khan Shahid M. , Franke-Fayard Blandine , Janse Chris J. , Obbard Darren J. , Reece Sarah E.
Published: April 2015

Sexual reproduction is an obligate step in the life cycle of many parasites, including the causative agents of malaria (Plasmodium). Mixed-species infections are common in nature and consequently, interactions between heterospecific gametes occur. Given the importance of managing gene flow across parasite populations, remarkably little is understood about how reproductive isolation between species is maintained. We use the rodent malaria parasitesP. bergheiandP. yoeliito investigate the ecology of mixed-species mating groups, identify proteins involved in pre-zygotic barriers, and examine their evolution. Specifically, we show that (i) hybridization occurs, but at low frequency; (ii) hybridization reaches high levels when female gametes lack the surface proteins P230 or P48/45, demonstrating that these proteins are key for pre-zygotic reproductive isolation; (iii) asymmetric reproductive interference occurs, where the fertility ofP. bergheigametes is reduced in the presence ofP. yoeliiand (iv) as expected for gamete recognition proteins, strong positive selection acts on a region of P230 and P47 (P48/45 paralogue). P230 and P48/45 are leading candidates for interventions to block malaria transmission. Our results suggest that depending on the viability of hybrids, applying such interventions to populations where mixed-species infections occur could either facilitate or hinder malaria control.
Tight coupling of primary production and marine mammal reproduction in the Southern Ocean
Authors: Paterson J. Terrill , Rotella Jay J. , Arrigo Kevin R. , Garrott Robert A.
Published: April 2015

Polynyas are areas of open water surrounded by sea ice and are important sources of primary production in high-latitude marine ecosystems. The magnitude of annual primary production in polynyas is controlled by the amount of exposure to solar radiation and sensitivity to changes in sea-ice extent. The degree of coupling between primary production and production by upper trophic-level consumers in these environments is not well understood, which prevents reliable predictions about population trajectories for species at higher trophic levels under potential future climate scenarios. In this study, we find a strong, positive relationship between annual primary production in an Antarctic polynya and pup production by ice-dependent Weddell seals. The timing of the relationship suggests reproductive effort increases to take advantage of high primary production occurring in the months after the birth pulse. Though the proximate causal mechanism is unknown, our results indicate tight coupling between organisms at disparate trophic levels on a short timescale, deepen our understanding of marine ecosystem processes, and raise interesting questions about why such coupling exists and what implications it has for understanding high-latitude ecosystems.
Predator mimicry, not conspicuousness, explains the efficacy of butterfly eyespots
Authors: De Bona Sebastiano , Valkonen Janne K. , López-Sepulcre Andrés , Mappes Johanna
Published: April 2015

Large conspicuous eyespots on butterfly wings have been shown to deter predators. This has been traditionally explained by mimicry of vertebrate eyes, but recently the classic eye-mimicry hypothesis has been challenged. It is proposed that the conspicuousness of the eyespot, not mimicry, is what causes aversion due to sensory biases, neophobia or sensory overloads. We conducted an experiment to directly test whether the eye-mimicry or the conspicuousness hypothesis better explain eyespot efficacy. We used great tits (Parus major) as model predator, and tested their reaction towards animated images on a computer display. Birds were tested against images of butterflies without eyespots, with natural-looking eyespots, and manipulated spots with the same contrast but reduced resemblance to an eye, as well as images of predators (owls) with and without eyes. We found that mimetic eyespots were as effective as true eyes of owls and more efficient in eliciting an aversive response than modified, less mimetic but equally contrasting eyespots. We conclude that the eye-mimicry hypothesis explains our results better than the conspicuousness hypothesis and is thus likely to be an important mechanism behind the evolution of butterfly eyespots.
Does natural selection favour taller stature among the tallest people on earth?
Authors: Stulp Gert , Barrett Louise , Tropf Felix C. , Mills Melinda
Published: April 2015

The Dutch are the tallest people on earth. Over the last 200 years, they have grown 20 cm in height: a rapid rate of increase that points to environmental causes. This secular trend in height is echoed across all Western populations, but came to an end, or at least levelled off, much earlier than in The Netherlands. One possibility, then, is that natural selection acted congruently with these environmentally induced changes to further promote tall stature among the people of the lowlands. Using data from the LifeLines study, which follows a large sample of the population of the north of The Netherlands (
n
= 94 516), we examined how height was related to measures of reproductive success (as a proxy for fitness). Across three decades (1935–1967), height was consistently related to reproductive output (number of children born and number of surviving children), favouring taller men and average height women. This was despite a later age at first birth for taller individuals. Furthermore, even in this low-mortality population, taller women experienced higher child survival, which contributed positively to their increased reproductive success. Thus, natural selection in addition to good environmental conditions may help explain why the Dutch are so tall.
Methanoculleus sediminis sp. nov., a methanogen from sediments near a submarine mud volcano
Authors: Chen Sheng-Chung , Chen Mei-Fei , Lai Mei-Chin , Weng Chieh-Yin , Wu Sue-Yao , Lin Saulwood , Yang Tsanyao F. , Chen Po-Chun
Published: April 2015

A mesophilic, hydrogenotrophic methanogen, strain S3FaT, was isolated from sediments collected by Ocean Researcher I cruise ORI-934 in 2010 near the submarine mud volcano MV4 located at the upper slope of south-west Taiwan. The methanogenic substrates utilized by strain S3FaTwere formate and H2/CO2but not acetate, secondary alcohols, methylamines, methanol or ethanol. Cells of strain S3FaTwere non-motile, irregular cocci, 0.5–1.0 μm in diameter. The surface-layer protein showed an Mr of 128 000.The optimum growth conditions were 37 °C, pH 7.1 and 0.17 M NaCl. The DNA G+C content of the genome of strain S3FaTwas 62.3 mol %. Phylogenetic analysis revealed that strain S3FaTwas most closely related toMethanoculleus marisnigriJR1T(99.3 % 16S rRNA gene sequence similarity). Genome relatedness between strain S3FaTandMethanoculleus marisnigriJR1Twas computed using both genome-to-genome distance analysis (GGDA) and average nucleotide identity (ANI) with values of 46.3–55.5 % and 93.08 %, respectively. Based on morphological, phenotypic, phylogenetic and genomic relatedness data, it is evident that strain S3FaTrepresents a novel species of the genusMethanoculleus, for which the nameMethanoculleus sediminissp. nov. is proposed. The type strain is S3FaT( = BCRC AR10044T = DSM 29354T).