bluuebunny/crossref_metadata_2025 huggingface dataset:
Maps
Authors: Hiatt Alfred
Published: June 2017

The presence of maps in the British Isles is attested from the early eighth century through to the end of the medieval period. Although relatively few pictorial maps survive from the Anglo‐Saxon period, literary texts and legal documents preserve evidence of a lively geographic culture. World maps (
mappae mundi
) were produced in significant numbers in England from the twelfth century onwards: the outstanding surviving example is the Hereford map (c. 1300). Extant examples of local maps suggest their usage in administrative and institutional contexts; surviving regional maps attest to a particular interest in the topography of the Holy Land within learned circles, and a tradition of maps of Britain best represented by the late fourteenth‐century Gough Map.
Paleography
Authors: Wakelin Daniel
Published: June 2017

This entry describes the history of the discipline of paleography, which is the study of ancient handwriting in order to transcribe and read from manuscripts, to date and locate those manuscripts based on their handwriting, and to trace the history of handwriting styles and practices. It discusses how dating, locating, and identification of manuscripts has been carried out over time, and considers pitfalls and controversies in these practices.
Unravelling the Genome by Genome Sequencing and Gene Function Analysis
Authors: Stiekema Willem J. , Pereira Andy
Published: June 2017

The sections in this article are

Introduction

Genome Sequencing

Strategies for Understanding Gene Function

Prospects

Acknowledgements
Metabolomics: Integrating the Metabolome and the Proteome for Systems Biology
Authors: Weckwerth Wolfram
Published: June 2017

The term ‘metabolome’ was coined in analogy to ‘genome’ and ‘proteome’ and relates to the metabolism. The metabolome contains all the characteristic metabolic activities of a cell or tissue and can be described on the basis of conversion rates, enzyme activities and intermediates, the set of metabolites. In order to study a cell, tissue or an organism in its entirety it is not sufficient to merely consider its metabolome alone. Only the interactions and synergisms between the transcriptome, the proteome and finally the metabolome will furnish the key to a functioning living system. This approach does not only promise to provide an improved picture of the metabolic processes and the interaction. In this way, we also hope to understand the function of hitherto unknown genes representing a large proportion of all so far published genomes. Finally, computer models for making predictions of the metabolic network and their iterative linkage to experimental data via the interaction of proteins and metabolic processes may contribute to studying fundamental mechanisms of metabolism.
Lateral Root Formation
Authors: Malamy Jocelyn E.
Published: June 2017

The plant root system is formed through continuous production of lateral roots. Lateral root formation can be divided into several discrete developmental stages. Correct progression through each stage is regulated by intrinsic developmental pathways and environmental response pathways. Similarly, the spacing and position of lateral roots in the root system are constrained by intrinsic developmental pathways, but are also responsive to environmental cues. Studies inArabidopsisand other plants have provided extensive information about the hormones and genes that regulate lateral root formation, and these studies are reviewed, with an emphasis on the role of the phytohormone auxin. The overall architecture of the root system, which is primarily determined by the number and placement of lateral roots, is a key determinant of plant survival and crop yield, particularly under conditions of water or nutrient stress. Therefore, understanding the regulatory mechanisms that control lateral root formation has important applications to agriculture. Our progress in leveraging our molecular understanding of lateral root formation to improve crops is discussed.
Studying Root Development Using a Genomic Approach
Authors: Dinneny Jose R. , Benfey Philip N.
Published: June 2017

The completion of the
Arabidopsis thaliana
genome sequencing project represented the beginning of a new way to approach biological questions in plants (The Arabidopsis Genome Initiative, 2000). At a basic level, a fully sequenced genome makes it possible to predict the identity and structure of most genes. This information, in conjunction with recent advances in technology to quantitatively detect the expression of thousands of genes simultaneously, has greatly expanded the number of genes a biologist can study. Thus, the postgenome era is characterized by a wealth of data, but also by new challenges. Large data sets require analytical methods such as statistical analysis and computationally intensive methods, with which most biologists are not necessarily familiar. To address these challenges, the new biologist must collaborate with researchers from other fields such as computer science and engineering, to design experiments, interpret data, generate models and build bioinformatics infrastructure to share data. While large data sets facilitate rapid progress using traditional reductionist approaches to answering biological questions, they also enable a new approach termed
systems biology
that aims to understand the structure of large‐scale phenomena not easily studied through the examination of individual genes. In this chapter, we will give an overview of the technologies that allow the root developmental biologist to acquire large data sets and examine how these techniques have been used to study root development. Finally, we will explore the types of questions that remain in root developmental biology for which genomic approaches are likely to provide useful insights.
Solution Processed Boron Nitride Nanosheets: Synthesis, Assemblies and Emerging Applications
Authors: Luo Wei , Wang Yanbin , Hitz Emily , Lin Yi , Yang Bao , Hu Liangbing
Published: June 2017

In the last decade, few‐layer boron nitride nanosheets and monolayer BN nanosheet (BNNS) have gained much attention due to their unique physical and chemical properties. To date, BNNS can be produced by micromechanical cleavage of BN crystal, unzipping BN nanotubes, chemical vapor deposition (CVD), and solution processed exfoliation from bulk BN powder. Due to the low cost and abundance of bulk BN powder and its simple processing for potentially scalable production, great efforts have been devoted toward solution processed exfoliation. In this feature article, recent significant advances in solution processed synthesis of BNNS are summarized. In particular, the solvent choice for one‐step BN exfoliation is highlighted. Multi‐dimensional assemblies consisting of BNNS are discussed, such as BN fiber, BN paper, and BN aerogel. The emerging applications of BNNS in different fields are then focused on, especially in barrier materials, dielectrics, catalysts, and thermal management.
Interfacial Charge Engineering in Ferroelectric‐Controlled Mott Transistors
Authors: Chen Xuegang , Zhang Xin , Koten Mark A. , Chen Hanghui , Xiao Zhiyong , Zhang Le , Shield Jeffrey E. , Dowben Peter A. , Hong Xia
Published: June 2017

Heteroepitaxial coupling at complex oxide interfaces presents a powerful tool for engineering the charge degree of freedom in strongly correlated materials, which can be utilized to achieve tailored functionalities that are inaccessible in the bulk form. Here, the charge‐transfer effect between two strongly correlated oxides, Sm0.5Nd0.5NiO3 (SNNO) and La0.67Sr0.33MnO3 (LSMO), is exploited to realize a giant enhancement of the ferroelectric field effect in a prototype Mott field‐effect transistor. By switching the polarization field of a ferroelectric Pb(Zr,Ti)O3 (PZT) gate, nonvolatile resistance modulation in the Mott transistors with single‐layer SNNO and bilayer SNNO/LSMO channels is induced. For the same channel thickness, the bilayer channels exhibit up to two orders of magnitude higher resistance‐switching ratio at 300 K, which is attributed to the intricate interplay between the charge screening at the PZT/SNNO interface and the charge transfer at the SNNO/LSMO interface. X‐ray absorption spectroscopy and X‐ray photoelectron spectroscopy studies of SNNO/LSMO heterostructures reveal about 0.1 electron per 2D unit cell transferred between the interfacial Mn and Ni layers, which is corroborated by first‐principles density functional theory calculations. The study points to an effective strategy to design functional complex oxide interfaces for developing high‐performance nanoelectronic and spintronic applications.
Lead‐Free Antiferroelectric Silver Niobate Tantalate with High Energy Storage Performance
Authors: Zhao Lei , Liu Qing , Gao Jing , Zhang Shujun , Li Jing‐Feng
Published: June 2017

Antiferroelectric materials that display double ferroelectric hysteresis loops are receiving increasing attention for their superior energy storage density compared to their ferroelectric counterparts. Despite the good properties obtained in antiferroelectric La‐doped Pb(Zr,Ti)O3‐based ceramics, lead‐free alternatives are highly desired due to the environmental concerns, and AgNbO3 has been highlighted as a ferrielectric/antiferroelectric perovskite for energy storage applications. Enhanced energy storage performance, with recoverable energy density of 4.2 J cm−3 and high thermal stability of the energy storage density (with minimal variation of ≤±5%) over 20–120 °C, can be achieved in Ta‐modified AgNbO3 ceramics. It is revealed that the incorporation of Ta to the Nb site can enhance the antiferroelectricity because of the reduced polarizability of B‐site cations, which is confirmed by the polarization hysteresis, dielectric tunability, and selected‐area electron diffraction measurements. Additionally, Ta addition in AgNbO3 leads to decreased grain size and increased bulk density, increasing the dielectric breakdown strength, up to 240 kV cm−1 versus 175 kV cm−1 for the pure counterpart, together with the enhanced antiferroelectricity, accounting for the high energy storage density.
Wearable Sensing Systems with Mechanically Soft Assemblies of Nanoscale Materials
Authors: Lee Youngsik , Kim Jaemin , Joo Hyunwoo , Raj Milan S. , Ghaffari Roozbeh , Kim Dae‐Hyeong
Published: June 2017

Emerging classes of wearable sensing systems that measure motion, physiological, electrophysiological, and electrochemical signals emanating from the human body have driven significant advances in clinical and academic research. These wearable systems rely on important breakthroughs in micro/nano‐electronics, information technology, and materials science. Compared to conventional bulk materials, nanomaterials with zero, one, and two dimensional (0D, 1D, and 2D) architectures exhibit unusual physical properties that could dramatically improve the performance of sensors. By integrating high performance sensors with soft and stretchable electronics, research groups are enabling fully‐integrated multifunctional sensing systems in skin‐worn formats, optimized for managing specific disease models. In this progress report, recent advances in soft wearable sensing systems based on assemblies of 0D, 1D, and 2D nanomaterials, unpackaged integrated circuits, and highly elastic (moisture resistant) encapsulating layers are reviewed. These advanced bioelectronic constructs combine multimodal sensor arrays, data storage elements, wireless data transmission modules, and actuators for continuous monitoring. The soft wearable systems that embody these unusual electronic materials and soft packaging strategies are beginning to impact big data analysis, remote health monitoring, and transdermal drug delivery applications, by transitioning from primary research discoveries to commercial adoption.
The self‐healing cross‐linked polyurethane by Diels–Alder polymerization
Authors: Wei Yanyan , Ma Xiaoyue
Published: June 2017

Polymer materials containing Diels–Alder (abbreviated DA) groups show good self‐healing ability under certain conditions. In this study, the thermal reversible DA bond was introduced into polyurethane by the design of molecular chain to obtain the self‐healing properties. The pre‐polyurethane (HTK) end‐capped with furan rings was synthesized by hexamethylene diisocyanate trimer and furfuryl alcohol firstly. Then, HTK was mixed with bismaleimide (BMI) to synthesize the cross‐linked polyurethane HTK‐PU. Finally, the properties of the HTK‐PU were characterized. It can be observed from DSC that the DA reaction occurred at 76°C and the r‐DA reaction occurred at 109.5°C. This cross‐linked polyurethane shows a remarkable high hardness (shore D80). When preserved at 80°C for 6 hr, the self‐healing efficiency of the HTK‐PU was 53.75% known from tensile test, and cracks on it virtually disappeared as observed from polarizing microscope (POM). When preserved at 80°C for 12 hr, the self‐healing efficiency was 67.56%.
Predictive validity of body fat percentage by bioimpedance compared with deuterium oxide dilution in Costa Rican schoolchildren
Authors: Zamora Salas Juan Diego , Laclé‐Murray Adriana
Published: June 2017

Objective

The purpose of this study was to verify the validity of body fat percentage (BF%) by bioelectrical impedance analysis (BIA) in a sample of Costa Rican schoolchildren.

METHODS

The sample consisted of 52 male (mean age 8.1 ± 0.9 years) and 49 female (mean age 7.5 ± 1.0 years) schoolchildren. Deuterium oxide dilution was the reference method used as the “gold standard” to determine the fat mass (FM) expressed as BF%. Linear regression analyses and paired sample t‐tests were used to test the association and mean differences between BIA and deuterium oxide dilution BF%. Concordance between BIA and deuterium oxide dilution BF% was determined by Lin's concordance correlation coefficient. Measurement of agreement between the two methods was analyzed using the Bland‐Altman procedure.

RESULTS

Significant associations between BIA and deuterium oxide dilution BF% were found in males (R = 0.97, R2 = 0.95, P < .0001) and in females (R = 0.98, R2 = .96, P < .0001). The measurements of BF% (mean ± SD) were not significantly different between males (BIA 31.1 ± 7.6% vs. deuterium oxide dilution 31.0 ± 7.4%) and females (BIA 25.9 ± 7.9% vs. deuterium oxide dilution 26.3 ± 7.8%) by t‐test. Lin's concordance correlation coefficient identified an almost perfect strength of agreement between males and females. Bland‐Altman plots showed that the Bodystat measured similar BF% compared to the deuterium oxide dilution in both males and females.

CONCLUSIONS

BIA Bodystat presented high agreement with BF% measured by deuterium oxide dilution; therefore BIA Bodystat is recommended for estimating BF% in Costa Rican schoolchildren.
Motor performance in children with Noonan syndrome
Authors: Croonen Ellen A. , Essink Marlou , van der Burgt Ineke , Draaisma Jos M. , Noordam Cees , Nijhuis‐van der Sanden Maria W. G.
Published: June 2017

Although problems with motor performance in daily life are frequently mentioned in Noonan syndrome, the motor performance profile has never been systematically investigated. The aim of this study was to examine whether a specific profile in motor performance in children with Noonan syndrome was seen using valid norm‐referenced tests. The study assessed motor performance in 19 children with Noonan syndrome (12 females, mean age 9 years 4 months, range 6 years 1 month to 11 years and 11 months, SDS 1 year and 11 months). More than 60% of the parents of the children reported pain, decreased muscle strength, reduced endurance, and/or clumsiness in daily functioning. The mean standard scores on the Visual Motor Integration (VMI) test and Movement Assessment Battery for Children 2, Dutch version (MABC‐2‐NL) items differed significantly from the reference scores. Grip strength, muscle force, and 6 min Walking Test (6 MWT) walking distance were significantly lower, and the presence of generalized hypermobility was significantly higher. All MABC‐2‐NL scores (except manual dexterity) correlated significantly with almost all muscle strength tests, VMI total score, and VMI visual perception score. The 6 MWT was only significantly correlated to grip strength. This is the first study that confirms that motor performance, strength, and endurance are significantly impaired in children with Noonan syndrome. Decreased functional motor performance seems to be related to decreased visual perception and reduced muscle strength. Research on causal relationships and the effectiveness of interventions is needed. Physical and/or occupational therapy guidance should be considered to enhance participation in daily life.
Expanded phenotypes and outcomes among 256 LGI1/CASPR2‐IgG–positive patients
Authors: Gadoth Avi , Pittock Sean J. , Dubey Divyanshu , McKeon Andrew , Britton Jeff W. , Schmeling John E. , Smith Aurelia , Kotsenas Amy L. , Watson Robert E. , Lachance Daniel H. , Flanagan Eoin P. , Lennon Vanda A. , Klein Christopher J.
Published: June 2017

Objective

To describe an expanded phenotypic spectrum and longitudinal outcome in 256 LGI1‐IgG–seropositive and/or CASPR2‐IgG–seropositive patients.

Methods

Patients were identified through service neural autoantibody evaluation. Ninety‐five had longitudinal follow‐up (7–456 months; median = 35).

Results

Among 3,910 patients tested, 196 were LGI1‐IgG positive, 51 were CASPR2‐IgG positive, and 9 were dual positive. Cerebrospinal fluid testing was less sensitive than serum testing, detecting only 24 of 38 (63%) LGI1‐IgG–positive and 5 of 6 (83%) CASPR2‐IgG–positive patients. LGI1‐IgG–positive specimens had higher voltage‐gated potassium channel–IgG immunoprecipitation values (0.33nmol/l, range = 0.02–5.14) than CASPR2‐IgG–positive specimens (0.10nmol/l, range = 0.00–0.45, p < 0.001). Of patients presenting with pain or peripheral nervous system (PNS) manifestations, 39% were LGI1‐IgG seropositive (7% had solely neuropathy or pain). Multivariate analysis identified age as the only significant predictor of central nervous system (CNS) versus PNS involvement (>50 years; odds ratio = 15, p < 0.001). Paroxysmal dizziness spells (PDS), a unique LGI1‐IgG accompaniment (14% of patients), frequently delayed the diagnosis. T2‐mesiotemporal hyperintensity was more common in LGI1‐IgG–positive (41%) than in CASPR2‐IgG–positive patients (p = 0.033). T1‐bright basal ganglia were confined to LGI1‐IgG–positive patients with faciobrachial–dystonic seizures (9 of 39, 31%). Cancer was found in 44% of LGI1‐IgG/CASPR2‐IgG dual seropositive patients (one‐third thymoma). Response to initial immunotherapy was favorable in 97%; mean modified Rankin score was 3 (range = 1–5) at onset and 1.74 (range = 0–6) at last follow‐up, with 9% having severe refractory disability, 20% being asymptomatic, 28% receiving immunotherapy, and 58% receiving antiepileptic medication.

Interpretation

Older age is a strong predictor of CNS involvement in patients seropositive for CASPR2‐IgG or LGI1‐IgG. Pain, peripheral manifestations, and stereotypic paroxysmal dizziness spells are common with LGI1‐IgG. Response to initial immunotherapy is often favorable, but some patients remain severely disabled, requiring long‐term immunotherapy and/or antiepileptic medications. Ann Neurol 2017;82:79–92
Phosphorylated neurofilament heavy chain: A biomarker of survival for C9ORF72‐associated amyotrophic lateral sclerosis
Authors: Gendron Tania F. , Daughrity Lillian M. , Heckman Michael G. , Diehl Nancy N. , Wuu Joanne , Miller Timothy M. , Pastor Pau , Trojanowski John Q. , Grossman Murray , Berry James D. , Hu William T. , Ratti Antonia , Benatar Michael , Silani Vincenzo , Glass Jonathan D. , Floeter Mary Kay , Jeromin Andreas , Boylan Kevin B. , Petrucelli Leonard ,   the C9ORF72 Neurofilament Study Group
Published: June 2017

As potential treatments for C9ORF72‐associated amyotrophic lateral sclerosis (c9ALS) approach clinical trials, the identification of prognostic biomarkers for c9ALS becomes a priority. We show that levels of phosphorylated neurofilament heavy chain (pNFH) in cerebrospinal fluid (CSF) predict disease status and survival in c9ALS patients, and are largely stable over time. Moreover, c9ALS patients exhibit higher pNFH levels, more rapid disease progression, and shorter survival after disease onset than ALS patients without C9ORF72 expansions. These data support the use of CSF pNFH as a prognostic biomarker for clinical trials, which will increase the likelihood of successfully developing a treatment for c9ALS. Ann Neurol 2017;82:139–146
Catalytic Enantioselective Reaction of Allenylnitriles with Imines Using Chiral Bis(imidazoline)s Palladium(II) Pincer Complexes
Authors: Kondo Masaru , Omori Masashi , Hatanaka Tsubasa , Funahashi Yasuhiro , Nakamura Shuichi
Published: June 2017

The first highly enantioselective reaction of allenylnitriles with imines has been developed. Excellent yields and enantioselectivities were observed for the reaction with various imines using chiral Phebim‐PdII complexes. This process offers a simple and efficient synthetic route for various functionalized α‐vinylidene‐β‐aminonitriles and their derivatives.
Von Lithium‐ zu Natriumionenbatterien: Vorteile, Herausforderungen und Überraschendes
Authors: Nayak Prasant Kumar , Yang Liangtao , Brehm Wolfgang , Adelhelm Philipp
Published: June 2017

Die mobile und stationäre Energiespeicherung durch wiederaufladbare Batterien ist ein Thema von breiter gesellschaftlicher und ökonomischer Bedeutung. Die wichtigste Technologie in diesem Bereich ist die Lithiumionenbatterie (LIB), jedoch muss man davon ausgehen, dass ein massiv wachsender LIB‐Markt ernsten Druck auf Ressourcen und Lieferketten ausüben wird. Seit kurzem richtet sich die Aufmerksamkeit daher auch wieder auf die Natriumionenbatterie (SIB), die eine preisgünstige Alternative darstellen könnte, die weniger anfällig für Ressourcen‐ und Versorgungsrisiken ist. Auf dem Papier scheint der Austausch von Lithium durch Natrium in einer Batterie unkompliziert, jedoch erlebt man in der Praxis oft unvorhersehbare Überraschungen. Was geschieht, wenn in Elektrodenreaktionen Lithium durch Natrium ersetzt wird? Dieser Aufsatz bietet einen aktuellen Überblick über das Redoxverhalten von Materialien bei ihrer Verwendung als Elektroden in LIBs bzw. SIBs. Die Vorteile und Herausforderungen im Zusammenhang mit der Verwendung von Natrium anstelle von Lithium werden diskutiert.
Cation‐Driven Self‐Assembly of a Gold(I)‐Based Metallo‐Tweezer
Authors: Ibáñez Susana , Poyatos Macarena , Peris Eduardo
Published: June 2017

A combination of self‐complementary π–π‐stacking interactions and metallophilic interactions triggered the self‐assembly of a new digold(I) metallo‐tweezer in the presence of several types of M+ ions. Titrations by fluorescence spectroscopy enabled the determination of the association constants of the resulting inclusion duplex complexes.
Design of a Tunable Self‐Oscillating Polymer with Ureido and Ru(bpy)3 Moieties
Authors: Masuda Tsukuru , Shimada Naohiko , Sasaki Taira , Maruyama Atsushi , Akimoto Aya Mizutani , Yoshida Ryo
Published: June 2017

An upper critical solution temperature (UCST)‐type self‐oscillating polymer was designed that exhibited rhythmic soluble–insoluble changes induced by the Belousov–Zhabotinsky (BZ) reaction. The target polymers were prepared by conjugating Ru(bpy)3, a catalyst for the BZ reaction, to ureido‐containing poly(allylamine‐co‐allylurea) (PAU) copolymers. The Ru(bpy)3‐conjugated PAUs exhibited a UCST‐type phase‐transition behavior, and the solubility of the polymer changed in response to the alternation in the valency of Ru(bpy)3. The ureido content influences the temperature range of self‐oscillation, and the oscillation occurred at higher temperatures than conventional LCST‐type self‐oscillating polymers. Furthermore, the self‐oscillating behavior of the Ru‐PAU could be regulated by addition of urea, which is a unique tuning strategy. We envision that novel self‐oscillating polymers with widely tunable soluble‐insoluble behaviors can be rationally designed based these UCST‐type polymers.
Dendronized Semiconducting Polymer as Photothermal Nanocarrier for Remote Activation of Gene Expression
Authors: Lyu Yan , Cui Dong , Sun He , Miao Yansong , Duan Hongwei , Pu Kanyi
Published: June 2017

Regulation of transgene systems is needed to develop innovative medicines. However, noninvasive remote control of gene expression has been rarely developed and remains challenging. We herein synthesize a near‐infrared (NIR) absorbing dendronized semiconducting polymer (DSP) and utilize it as a photothermal nanocarrier not only to efficiently deliver genes but also to spatiotemporally control gene expression in conjunction with heat‐inducible promoter. DSP has a high photothermal conversion efficiency (44.2 %) at 808 nm, permitting fast transduction of NIR light into thermal signals for intracellular activation of transcription. Such a DSP‐mediated remote activation can rapidly and safely result in 25‐ and 4.5‐fold increases in the expression levels of proteins in living cells and mice, respectively. This study thus provides a promising approach to optically regulate transgene systems for on‐demand therapeutic transgene dosing.
Determination of Radical–Radical Distances in Light‐Active Proteins and Their Implication for Biological Magnetoreception
Authors: Nohr Daniel , Paulus Bernd , Rodriguez Ryan , Okafuji Asako , Bittl Robert , Schleicher Erik , Weber Stefan
Published: June 2017

Light‐generated short‐lived radial pairs have been suggested to play pivotal roles in cryptochromes and photolyases. Cryptochromes are very probably involved in magnetic compass sensing in migratory birds and the magnetic‐field‐dependent behavior of insects. We examined photo‐generated transient states in the cryptochrome of Drosophila melanogaster and in the structurally related DNA‐repair enzyme Escherichia coli DNA photolyase. Using pulsed EPR spectroscopy, the exchange and dipolar contributions to the electron spin–spin interaction were determined in a straightforward and direct way. With these parameters, radical‐pair partners may be identified and the magnetoreceptor efficiency of cryptochromes can be evaluated. We present compelling evidence for an extended electron‐transfer cascade in the Drosophila cryptochrome, and identified W394 as a key residue for flavin photoreduction and formation of a spin‐correlated radical pair with a sufficient lifetime for high‐sensitivity magnetic‐field sensing.
Imprinted Photonic Hydrogels for the Size‐ and Shell‐Selective Recognition of Nanoparticles
Authors: Gam‐Derouich Sarra , Bourdillon Céline , Lakhdar Chaouche Soraya , Coolen Laurent , Maître Agnès , Mangeney Claire , Schwob Catherine
Published: June 2017

Sensors based on responsive photonic hydrogels have recently attracted considerable attention for visual medical diagnostics, pharmaceutical bioassays, and environmental monitoring. However, the use of these promising materials for the detection of nanoparticles (NPs) has never been explored so far, although the sensing of nanoobjects is a rapidly evolving area of research. To address this issue, we have combined the concepts of inverse‐opal hydrogels and nanoparticle‐imprinted polymers. In this way, we could obtain a NP‐imprinted photonic hydrogel consisting of a three‐dimensional, highly ordered poly(methacrylic acid) macroporous array, in which nanocavities complementary to the target NPs, in this case colloidal quantum dots, are distributed. This novel type of NP‐imprinted photonic hydrogel sensor was shown to display high sensitivity and selectivity, thus opening new prospects for the development of equipment‐free and cost‐efficient sensing devices for NPs.
Studying the Conformation of a Receptor Tyrosine Kinase in Solution by Inhibitor‐Based Spin Labeling
Authors: Yin Dongsheng M. , Hannam Jeffrey S. , Schmitz Anton , Schiemann Olav , Hagelueken Gregor , Famulok Michael
Published: June 2017

The synthesis of a spin label based on PD168393, a covalent inhibitor of a major anticancer drug target, the epidermal growth factor receptor (EGFR), is reported. The label facilitates the analysis of the EGFR structure in solution by pulsed electron paramagnetic resonance (EPR) spectroscopy. For various EGFR constructs, including near‐full‐length EGFR, we determined defined distance distributions between the two spin labels bound to the ATP binding sites of the EGFR dimer. The distances are in excellent agreement with an asymmetric dimer of the EGFR. Based on crystal structures, this dimer had previously been proposed to reflect the active conformation of the receptor but structural data demonstrating its existence in solution have been lacking. More generally, our study provides proof‐of‐concept that inhibitor‐based spin labeling enables the convenient introduction of site‐specific spin labels into kinases for which covalent or tight‐binding small‐molecule modulators are available.
Discovery of a Calcium‐Dependent Enzymatic Cascade for the Selective Assembly of Hapalindole‐Type Alkaloids: On the Biosynthetic Origin of Hapalindole U
Authors: Zhu Qin , Liu Xinyu
Published: June 2017

Hapalindole U (4) is a validated biosynthetic precursor to ambiguine alkaloids (Angew. Chem. Int. Ed. 2016, 55, 5780), of which biogenetic origin remains unknown. The recent discovery of AmbU4 (or FamC1) protein encoded in the ambiguine biosynthetic pathway (J. Am. Chem. Soc. 2015, 137, 15366), an isomerocyclase that can rearrange and cyclize geranylated indolenine (2) to a previously unknown 12‐epi‐hapalindole U (3), raised the question whether 3 is a direct precursor to 4 or an artifact arising from the limited in vitro experiments. Here we report a systematic approach that led to the discovery of an unprecedented calcium‐dependent AmbU1‐AmbU4 enzymatic complex for the selective formation of 4. This discovery refuted the intermediacy of 3 and bridged the missing links in the early‐stage biosynthesis of ambiguines. This work further established the isomerocyclases involved in the biogenesis of hapalindole‐type alkaloids as a new family of calcium‐dependent enzymes, where the metal ions are shown critical for their enzymatic activities and selectivities.
Opto‐electrochemical In Situ Monitoring of the Cathodic Formation of Single Cobalt Nanoparticles
Authors: Brasiliense Vitor , Clausmeyer Jan , Dauphin Alice L. , Noël Jean‐Marc , Berto Pascal , Tessier Gilles , Schuhmann Wolfgang , Kanoufi Fréderic
Published: June 2017

Single‐particle electrochemistry at a nanoelectrode is explored by dark‐field optical microscopy. The analysis of the scattered light allows in situ dynamic monitoring of the electrodeposition of single cobalt nanoparticles down to a radius of 65 nm. Larger sub‐micrometer particles are directly sized optically by super‐localization of the edges and the scattered light contains complementary information concerning the particle redox chemistry. This opto‐electrochemical approach is used to derive mechanistic insights about electrocatalysis that are not accessible from single‐particle electrochemistry.
Biologically Controlled Morphology and Twinning in Guanine Crystals
Authors: Hirsch Anna , Palmer Benjamin A. , Elad Nadav , Gur Dvir , Weiner Steve , Addadi Lia , Kronik Leeor , Leiserowitz Leslie
Published: June 2017

Guanine crystals are widely used in nature as components of multilayer reflectors. Guanine‐based reflective systems found in the copepod cuticle and in the mirror of the scallop eye are unique in that the multilayered reflectors are tiled to form a contiguous packed array. In the copepod cuticle, hexagonal crystals are closely packed to produce brilliant colors. In the scallop eye, square crystals are tiled to obtain an image‐forming reflecting mirror. The tiles are about 1 μm in size and 70 nm thick. According to analysis of their electron diffraction patterns, the hexagon and square tiles are not single crystals. Rather, each tile type is a composite of what appears to be three crystalline domains differently oriented and stacked onto one another, achieved through a twice‐repeated twinning about their ⟨011⟩ and ⟨021⟩ crystal axes, respectively. By these means, the monoclinic guanine crystal mimics higher symmetry hexagonal and tetragonal structures to achieve unique morphologies.
Silver‐Catalyzed Stereoselective Aminosulfonylation of Alkynes
Authors: Ning Yongquan , Ji Qinghe , Liao Peiqiu , Anderson Edward A. , Bi Xihe
Published: June 2017

A silver‐catalyzed intermolecular aminosulfonylation of terminal alkynes with sodium sulfinates and TMSN3 is reported. This three‐component reaction proceeds through sequential hydroazidation of the terminal alkyne and addition of a sulfonyl radical to the resultant vinyl azide. The method enables the stereoselective synthesis of a wide range of β‐sulfonyl enamines without electron‐withdrawing groups on the nitrogen atom. These enamines are found to be suitable for a variety of further transformations.
Bending, Curling, Rolling, and Salient Behavior of Molecular Crystals Driven by [2+2] Cycloaddition of a Styrylbenzoxazole Derivative
Authors: Wang Haoran , Chen Peng , Wu Zhu , Zhao Jinyu , Sun Jingbo , Lu Ran
Published: June 2017

We report interesting photomechanical behaviors of the dynamic molecular crystals of (E)‐2‐(2,4‐dichlorostyryl)benzo[d]oxazole (BOACl24). The photosalient effect of the rod‐like crystal based on a metal‐free olefin driven by photodimerization is observed. Moreover, the needle‐like crystals of BOACl24 exhibit a reversible bending away from a UV light source. The nanofibers curl easily under UV irradiation in an organogel, in which the photo‐induced rolling of a small slice occurs. This suggests that the rapid release of the accumulated strain during photodimerization may lead to a photosalient effect, and the bending or curling happens when the strain is released slowly. Notably, [2+2] cycloaddition takes place between two different conformational isomers of BOACl24 on account of the rotation of the benzoxazole ring around the C−C bond in an excited state before photodimerization. Such topo‐photochemical reaction has not been reported elsewhere.
Synthesis, characterization, and performance evaluation of PES/EDA‐functionalized TiO2 mixed matrix membranes for CO2/CH4 separation
Authors: Eltahir Mustafa Sara Galal Eldin , Mannan Hafiz Abdul , Nasir Rizwan , Mohshim Dzeti Farhah , Mukhtar Hilmi
Published: June 2017

Poor adhesion between hydrophobic polymers and hydrophilic inorganic fillers is a challenge that encumbers a high separation performance of mixed matrix membrane (MMM). In this study, Titanium(IV) oxide (TiO2) nanoparticles were functionalized using ethylenediamine (EDA) before embedment in poly(ether sulfone) (PES) polymer matrix. MMMs were synthesized through dry phase inversion technique. Membranes morphology and nanoparticles dispersion was drastically enhanced posterior amine modification indicating an improved adhesion between the polymer and filler particles. Membranes thermal stability was likewise improved as higher degradation temperatures were perceived for PES/EDA–TiO2 MMMs. Gas separation evaluation for pure carbon dioxide (CO2) and methane (CH4) gases revealed a remarkably enhanced separation performance upon amine‐grafting of TiO2 as EDA‐TiO2 MMMs exhibited a higher separation performance as compared to MMMs with pristine TiO2. The highest ideal separation factor achieved was 41.52 with CO2 permeability of 10.11 Barrer at an optimum loading of 5% wt of EDA‐TiO2 which is threefold higher as compared to neat PES membrane and approximately twofold higher than MMMs with pristine TiO2, respectively, at the same filler loading. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45346.
NiCo2S4 Materials for Supercapacitor Applications
Authors: Gao Yong‐Ping , Huang Ke‐Jing
Published: June 2017

Cobalt–nickel sulfide (NiCo2S4) shows extensive potential for innovative photoelectronic and energetic materials owing to distinctive physical and chemical properties. In this review, representative strategies for the fabrication and application of NiCo2S4 and composite nanostructures are outlined for supercapacitors, with the aim of promoting the development of NiCo2S4 and their composites in the supercapacitor field through an analysis and comparison of diverse nanostructures. A brief introduction into the structures, properties, and morphologies are presented. Further prospects and promising developments of the materials in the supercapacitor field are also proposed.
Two stochastic dominance criteria based on tail comparisons
Authors: Mulero Julio , Sordo Miguel A. , de Souza Marilia C. , Suárez‐LLorens Alfonso
Published: June 2017

Actuarial risks and financial asset returns are typically heavy tailed. In this paper, we introduce 2 stochastic dominance criteria, called the right‐tail order and the left‐tail order, to compare these variables stochastically. The criteria are based on comparisons of expected utilities, for 2 classes of utility functions that give more weight to the right or the left tail (depending on the context) of the distributions. We study their properties, applications, and connections with other classical criteria, including the increasing convex and the second‐order stochastic dominance. Finally, we rank some parametric families of distributions and provide empirical evidence of the new stochastic dominance criteria with an example using real data.
Human exposure to power frequency magnetic fields up to 7.6 mT: An integrated EEG/fMRI study
Authors: Modolo Julien , Thomas Alex W. , Legros Alexandre
Published: June 2017

We assessed the effects of power‐line frequency (60 Hz in North America) magnetic fields (MF) in humans using simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). Twenty‐five participants were enrolled in a pseudo‐double‐blind experiment involving “real” or “sham” exposure to sinusoidal 60 Hz MF exposures delivered using the gradient coil of an MRI scanner following two conditions: (i) 10 s exposures at 3 mT (10 repetitions); (ii) 2 s exposures at 7.6 mT (100 repetitions). Occipital EEG spectral power was computed in the alpha range (8–12 Hz, reportedly the most sensitive to MF exposure in the literature) with/without exposure. Brain functional activation was studied using fMRI blood oxygen level‐dependent (BOLD, inversely correlated with EEG alpha power) maps. No significant effects were detected on occipital EEG alpha power during or post‐exposure for any exposure condition. Consistent with EEG results, no effects were observed on fMRI BOLD maps in any brain region. Our results suggest that acute exposure (2–10 s) to 60 Hz MF from 3 to 7.6 mT (30,000 to 76,000 times higher than average public exposure levels for 60 Hz MF) does not induce detectable changes in EEG or BOLD signals. Combined with previous findings in which effects were observed on the BOLD signal after 1 h exposure to 3 mT, 60 Hz MF, this suggests that MF exposure in the low mT range (<10 mT) might require prolonged durations of exposure to induce detectable effects. Bioelectromagnetics. 38:425–435, 2017. © 2017 Wiley Periodicals, Inc.
Engineering CHO cells with an oncogenic KIT improves cells growth, resilience to stress, and productivity
Authors: Mahameed Mohamed , Tirosh Boaz
Published: June 2017

An optimized biomanufacturing process in mammalian cells is contingent on the ability of the producing cells to reach high viable cell densities. In addition, at the peak of growth, cells need to continue producing the biological entity at a consistent quality. Thus, engineering cells with robust growth performance and resilience to variable stress conditions is highly desirable. The tyrosine kinase receptor, KIT, plays a key role in cell differentiation and the survival of several immune cell types. Its oncogenic mutant, D816V, endows cells with high proliferation capacity, and resistance to kinase inhibitors. Importantly, this onco‐KIT mutant when introduced into various cell types is arrested in the endoplasmic reticulum in a constitutively active form. Here, we investigated the effect of oncogenic D816V KIT on the performance of CHO‐K1 cells under conventional tissue culture growth settings and when adapted, to shaking conditions. The onco‐KIT promoted global protein synthesis, elevated the expression of a secretable transgene, enhanced proliferation, and improved the overall titers of a model glycoprotein. Moreover, the expression of the onco‐KIT endowed the cells with a remarkable resistance to various stress conditions. Our data suggest that the introduction of onco‐KIT can serve as a strategy for improving glycoprotein biomanufacturing. Biotechnol. Bioeng. 2017;114: 2560–2570. © 2017 Wiley Periodicals, Inc.
Chemistry of Two Distinct Aeolid Spurilla Species: Ecological Implications
Authors: Ciavatta Maria Letizia , García‐Matucheski Stella , Carbone Marianna , Villani Guido , Nicotera Maria Rosaria , Muniain Claudia , Gavagnin Margherita
Published: June 2017

The lipophilic extracts of two marine aeolid nudibranch molluscs of the genus Spurilla collected in distinct geographical areas have been chemically analyzed. The Et2O extracts of the nudibranchs were dominated by the presence of usual fatty acids and sterols and contained terpenoid compounds 1 – 3 as minor metabolites. Spurillin A (1) and spurillin B (3) were new molecules whereas cis‐γ‐monocyclofarnesol (2) was already reported in the literature as a synthesis product. Interestingly, bursatellin (4), previously isolated from anaspidean molluscs of the genus Bursatella, was found in the butanol extract of both Spurilla species. Compounds 1 – 4 were not detected in the extracts of the sea‐anemone preys collected together with the molluscs.
Analysis of Structure–Activity Relationships Based on the Hepatitis C Virus SLIIb Internal Ribosomal Entry Sequence RNA‐Targeting GGHYRFK⋅Cu Complex
Authors: Ross Martin James , Fidai Insiya , Cowan James A.
Published: June 2017

New therapeutics for targeting the hepatitis C virus (HCV) have been released in recent years. Although they are less prone to resistance, they are still administered in cocktails as a combination of drugs targeting various aspects of the viral life cycle. Herein, we aim to contribute to an arsenal of new HCV therapeutics by targeting the HCV internal ribosomal entry sequence (IRES) RNA through the development of catalytic metallodrugs that function to degrade rather than inhibit the target molecule. Based on a previously characterized HCV IRES stem‐loop IIb RNA‐targeting metallopeptide Cu‐GGHYrFK (1⋅Cu), an all‐l analogue (3⋅Cu) and a series of additional complexes with single alanine substitutions in the targeting domain were prepared and screened to determine the influence each amino acid side chain on RNA localization and recognition, and catalytic reactivity toward the RNA. Additional substitutions of the tyrosine position in complex 3⋅Cu were also investigated. Good agreement between calculated and measured binding affinities provided support for in silico modeling of the SLIIb RNA binding site and correlations with RNA cleavage sites. Examination of the cleavage products from reaction of the Cu complexes with SLIIb provided mechanistic insights, with the first observation of the 5′‐geminal diol and 5′‐phosphopropenal as products through the use of a Cu⋅ATCUN catalytic motif. Together, the data yielded insights into structure–function relationships that will guide future optimization efforts.
Kinetic Selectivity and Thermodynamic Features of Competitive Imine Formation in Dynamic Covalent Chemistry
Authors: Kulchat Sirinan , Chaur Manuel N. , Lehn Jean‐Marie
Published: June 2017

The kinetic and thermodynamic selectivities of imine formation have been investigated for several dynamic covalent libraries of aldehydes and amines. Two systems were examined, involving the reaction of different types of primary amino groups (aliphatic amines, alkoxy‐amines, hydrazides and hydrazines) with two types of aldehydes, sulfobenzaldehyde and pyridoxal phosphate in aqueous solution at different pD (5.0, 8.5, 11.4) on one hand, 2‐pyridinecarboxaldehyde and salicylaldehyde in organic solvents on the other hand. The reactions were performed separately for given amine/aldehyde pairs as well as in competitive conditions between an aldehyde and a mixture of amines. In the latter case, the time evolution of the dynamic covalent libraries generated was followed, taking into consideration the operation of both kinetic and thermodynamic selectivities. The results showed that, in aqueous solution, the imine of the aliphatic amine was not stable, but oxime and hydrazone formed well in a pH dependent way. On the other hand, in organic solvents, the kinetic product was the imine derived from an aliphatic amine and the thermodynamic products were oxime and hydrazone. The insights gained from these experiments provide a basis for the implementation of imine formation in selective derivatization of mono‐amines in mixtures as well as of polyfunctional compounds presenting different types of amino groups. They may in principle be extended to other dynamic covalent chemistry systems.
A Flexible, Fused, Azomethine–Boron Complex: Thermochromic Luminescence and Thermosalient Behavior in Structural Transitions between Crystalline Polymorphs
Authors: Ohtani Shunsuke , Gon Masayuki , Tanaka Kazuo , Chujo Yoshiki
Published: June 2017

This manuscript reports the multi‐functional boron complex presenting aggregation‐induced emission (AIE), crystallization‐induced emission enhancement (CIEE), and thermosalient behavior accompanying thermochromic luminescence during crystal–crystal transitions by employing the fused azomethine ligand. In particular, we propose that these properties can be explained by molecular “flexibility” toward external stimuli, including temperature changes and photo‐excitation, and two types of crystal polymorphs with different absorption and luminescent properties were obtained. Optical measurements indicated that both polymorphs showed individual AIE and strong CIEE properties. From the investigations, the boron complex showed large structural relaxation and formed the bent structure in the excited state, followed by emission annihilation in the absence of structural restriction. In addition, it was shown that interconversion between these polymorphs could be reversibly induced by heating and cooling. The data from the single‐crystal X‐ray analyses suggested that alteration of crystal packing and intermolecular interaction should influence the luminescent chromism. Moreover, we also found that the crystals showed unusual mechanical behavior, such as hopping and fragmentation by heating and cooling, respectively, which is called thermosalient behavior. It was suggested that the loosely‐fused structure could be responsible for expressing unique optical and mechanical properties.
Labeling and Magnetic Resonance Imaging of Exosomes Isolated from Adipose Stem Cells
Authors: Busato Alice , Bonafede Roberta , Bontempi Pietro , Scambi Ilaria , Schiaffino Lorenzo , Benati Donatella , Malatesta Manuela , Sbarbati Andrea , Marzola Pasquina , Mariotti Raffaella
Published: June 2017

Adipose stem cells (ASC) represent a promising therapeutic approach for neurodegenerative diseases. Most biological effects of ASC are probably mediated by extracellular vesicles, such as exosomes, which influence the surrounding cells. Current development of exosome therapies requires efficient and noninvasive methods to localize, monitor, and track the exosomes. Among imaging methods used for this purpose, magnetic resonance imaging (MRI) has advantages: high spatial resolution, rapid in vivo acquisition, and radiation‐free operation. To be detectable with MRI, exosomes must be labeled with MR contrast agents, such as ultra‐small superparamagnetic iron oxide nanoparticles (USPIO). Here, we set up an innovative approach for exosome labeling that preserves their morphology and physiological characteristics. We show that by labeling ASC with USPIO before extraction of nanovesicles, the isolated exosomes retain nanoparticles and can be visualized by MRI. The current work aims at validating this novel USPIO‐based exosome labeling method by monitoring the efficiency of the labeling with MRI both in ASC and in exosomes. © 2017 by John Wiley & Sons, Inc.