bluuebunny/crossref_metadata_2025 huggingface dataset:
Interannual Variations of Surface Currents and Transports in the Sicily Channel Derived From Coastal Altimetry
Authors: Jebri Fatma , Zakardjian Bruno , Birol Florence , Bouffard Jérôme , Jullion Loïc , Sammari Cherif
Published: November 2017

A 20 year coastal altimetry data set (X‐TRACK) is used, for the first time, to gain insight into the long‐term interannual variations of the surface circulation in the Sicily Channel. First, a spectral along with a time/space diagram analysis are applied to the monthly means. They reveal a regionally coherent current patterns from track to track with a marked interannual variability that is unequally shared between the Atlantic Tunisian Current and Atlantic Ionian Stream inflows in the Sicily Channel and the Bifurcation Tyrrhenian Current outflow northeast of Sicily. Second, an empirical altimetry‐based transport‐like technique is proposed to quantify volume budgets inside the closed boxes formed by the crossing of the altimetry tracks and coastlines over the study area. A set of hydrographic measurements is used to validate the method. The inferred altimetry transports give a well‐balanced mean eastward Atlantic Waters baroclinic flow of 0.4 Sv and standard deviations of 0.2 Sv on a yearly basis throughout the Sicily Channel and toward the Ionian Sea, which is fairly coherent with those found in the literature. Furthermore, the analysis allows to quantify the intrusions of Atlantic Waters over the Tunisian Shelf (0.12 ± 0.1 Sv) and highlights two main modes of variability of the main surface waters path over the Sicily Channel through the Bifurcation Atlantic Tunisian Current and Atlantic Ionian Stream systems. Some physical mechanisms are finally discussed with regards to changes in the observed currents and transports.
Dynamical Evolution of Intense Ierapetra Eddies on a 22 Year Long Period
Authors: Ioannou Artemis , Stegner Alexandre , Le Vu Briac , Taupier‐Letage Isabelle , Speich Sabrina
Published: November 2017

Considered as wind forced, the recurrent formation of Ierapetra eddy affects the Eastern Mediterranean Sea circulation. Even though this large, coherent, and long‐lived anticyclone has been extensively studied, there are only few quantitative information on its dynamical characteristics. The main goal of this study is to quantify the Ierapetra eddies (IEs) intensity and examine their seasonal and interannual variability over a 22 year period (1993–2014). We choose the automatic eddy detection algorithm AMEDA to estimate the main IEs dynamical parameters such as their size, their intensities, and their lifetimes. Applied to daily AVISO altimetric products, the AMEDA allows a full eddy characterization providing additional information on vortex velocity profiles as well as on merging and splitting events. Among the years of observations, the IEs Rossby number experience a strong variability and could vary by a factor 4 (Ro = 0.07–0.27). This is mainly due to the eddy velocity variations rather than size variations. Moreover, we found that after their formation IEs could reintensify. This intensification process may lead to a doubling of the vortex intensity in less than 4 months. That extra input of energy coincides with the Etesian winds period. Such high intensities are not expected from large‐scale anticyclones and require cyclogeostrophic corrections. Considering this ageostrophic part, the maximum values of the core vorticity were derived and we found that the IEs might sometimes exhibit a negative potential vorticity core. Evidences on the eddy intensity from two oceanographic campaigns suggest that the IEs are probably more intense than we even estimate.
Teapots, Dresses and Chairs
Authors: Retsin Gilles
Published: November 2017

Contrary to the impression given throughout this issue of 2, the future of the architectural profession is not to be found in scaling down to the level of household products and fashion items. So argues London‐based architect Gilles Retsin, who teaches at the Bartlett School of Architecture. While embracing transdisciplinarity and engagement with multiple scales in architectural practice and education, he sees these as evidence of a more research‐based turn, rather than an abandonment of architects' key calling. Although also opening up the profession to a product rather than service‐based business model, small‐scale objects essentially offer a context for experimentation with new technology that then begs to be scaled up.
Enhancing Therapeutic Efficacy of Combined Cancer Phototherapy by Ultrasound‐Mediated In Situ Conversion of Near‐Infrared Cyanine/Porphyrin Microbubbles into Nanoparticles
Authors: Xu Yunxue , Liang Xiaolong , Bhattarai Pravin , Sun Yang , Zhou Yiming , Wang Shumin , Chen Wen , Ge Huiyu , Wang Jinrui , Cui Ligang , Dai Zhifei
Published: November 2017

Nanoparticles (NPs)‐based diagnosis and phototherapy are emerging as the cutting‐edge technologies for detection and treatment of cancer but their applications are still limited since insufficient and heterogeneous NPs accumulation in cancer often causes recurrence. To overcome these limitations, multifunctional microbubbles (MBs) were constructed with 1, 1‐dioctadecyl‐3, 3, 3, 3‐tetramethylindotricarbocyanine iodide (DiR) and porphyrin grafted lipid (PGL). Both DiR and PGL self‐assembled as microbubbles, the as‐designed PGL‐DiR MBs possess remarkably high drug loading contents (5.8% PGL and 10.38% DiR) and stable co‐delivery drug combinations. In vivo experiments showed PGL‐DiR MBs could serve as an excellent ultrasound contrast agent to enhance ultrasound imaging greatly for identifying the location and size of the tumors. Upon exposure to ultrasound, in situ conversion of PGL‐DiR MBs into nanoparticles resulted in a remarkable increase in fluorescence intensity (~5 folds) in tumor compared with PGL‐DiR NPs, validating the enhanced tumor accumulation and cellular uptake of therapeutic agents. PGL‐DiR MBs showed complete tumor ablation without recurrence in vivo, while PGL‐DiR NPs showed only 72.6% tumor growth inhibition at the same dose. We believe that PGL‐DiR MBs will soon reach their full potential as an important class of phototherapeutic formulations and will contribute to remarkable advances in cancer treatments.
Schottky‐Barrier‐Controllable Graphene Electrode to Boost Rectification in Organic Vertical P–N Junction Photodiodes
Authors: Kim Jong Su , Choi Young Jin , Woo Hwi Je , Yang Jeehye , Song Young Jae , Kang Moon Sung , Cho Jeong Ho
Published: November 2017

Monolayer graphene is used as an electrode to develop novel electronic device architectures that exploit the unique, atomically thin structure of the material with a low density of states at its charge neutrality point. For example, a single semiconductor layer stacked onto graphene can provide a semiconductor–electrode junction with a tunable injection barrier, which is the basis for a primitive transistor architecture known as the Schottky barrier field‐effect transistor. This work demonstrates the next level of complexity in a vertical graphene–semiconductor architecture. Specifically, an organic vertical p‐n junction (p‐type pentacene/n‐type N,N′‐dioctyl‐3,4,9,10‐perylenedicarboximide (PTCDI‐C8)) on top of a graphene electrode constituting a novel gate‐tunable photodiode device structure is fabricated. The model device confirms that controlling the Schottky barrier height at the pentacene–graphene junction can (i) suppress the dark current density and (ii) enhance the photocurrent of the device, both of which are critical to improve the performance of a photodiode.
Triflic Acid as an Efficient Brønsted Acid Promoter for the Umpolung of N‐Ac Indoles in Hydroarylation Reactions
Authors: Nandi Raj Kumar , Perez‐Luna Alejandro , Gori Didier , Beaud Rodolphe , Guillot Régis , Kouklovsky Cyrille , Gandon Vincent , Vincent Guillaume
Published: November 2017

We report that triflic acid, a strong Brønsted acid, is a very powerful alternative to FeCl3 to mediate the hydroarylation of N−Ac indoles, which delivers regioselectively 3‐arylindolines, 3,3‐spiroindolines or 2‐arylindolines. Mechanistic explorations point towards the existence of a highly electrophilic intermediate by simultaneous activation of the acetyl and of the C2=C3 bond by protons.

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Flexible, Transparent, Sensitive, and Crosstalk‐Free Capacitive Tactile Sensor Array Based on Graphene Electrodes and Air Dielectric
Authors: Pyo Soonjae , Choi Jungwook , Kim Jongbaeg
Published: November 2017

The development of sensitive, flexible, and transparent tactile sensors is of great interest for next‐generation flexible displays and human–machine interfaces. Although a few materials and structural designs have been previously developed for high‐performance tactile sensors, achieving flexibility, full transparency, and highly sensitive multipoint recognition without crosstalk remains a significant challenge for such systems. This work demonstrates a capacitive tactile sensor composed of two sets of facing graphene electrodes separated by spacers, which forms an air dielectric between them. The air gap facilitates more effective deformation of the top graphene electrode under pressure compared to typical elastomer dielectrics, resulting in a high sensitivity of 6.55% kPa−1 and a fast response time of ≈70 ms. Taking advantage of the remarkable properties of graphene for electrode usage, the tactile sensor presents sufficient transparency (over 70% at 550 nm) as well as excellent electrical and mechanical flexibility for 500 cycles at a bending radius of 8 mm. Simulated and experimental results validate that the isolation of each tactile cell by the spacers allows the pixelated sensor array to recognize the spatial distribution of applied pressure without crosstalk. The proposed sensor would be a promising candidate for tactile sensing components that require both flexibility and transparency.
Predictive testing of minors for Huntington's disease: The UK and Netherlands experiences
Authors: Quarrell Oliver W. , Clarke Angus J. , Compton Cecilia , de Die‐Smulders Christine E.M. , Fryer Alan , Jenkins Sian , Lahiri Nayana , MacLeod Rhona , Miedzybrodzka Zosia , Morrison Patrick J. , Musgrave Hannah , O'Driscoll Mary , Strong Mark , van Belzen Martine J. , Vermeer Sascha , Verschuuren‐Bemelmans Corien C. , Bijlsma Emilia K.
Published: November 2017

A consistent feature of predictive testing guidelines for Huntington's disease (HD) is the recommendation not to undertake predictive tests on those < 18 years. Exceptions are made but the extent of, and reasons for, deviation from the guidelines are unknown. The UK Huntington's Prediction Consortium has collected data annually on predictive tests undertaken from the 23 UK genetic centers. DNA analysis for HD in the Netherlands is centralized in the Laboratory for Diagnostic Genome Analysis in Leiden. In the UK, 60 tests were performed on minors between 1994 and 2015 representing 0.63% of the total number of tests performed. In the Netherlands, 23 tests were performed on minors between 1997 and 2016. The majority of the tests were performed on those aged 16 and 17 years for both countries (23% and 57% for the UK, and 26% and 57% for the Netherlands). Data on the reasons for testing were identified for 36 UK and 22 Netherlands cases and included: close to the age of 18 years, pregnancy, currently in local authority care and likely to have less support available after 18 years, person never having the capacity to consent and other miscellaneous reasons. This study documents the extent of HD testing of minors in the UK and the Netherlands and suggests that, in general, the recommendation is being followed. We provide some empirical evidence as to reasons why clinicians have departed from the recommendation. We do not advise changing the recommendation but suggest that testing of minors continues to be monitored.
Trifluoromethylfluorosulfonylation of Unactivated Alkenes Using Readily Available Ag(O2CCF2SO2F) and N‐Fluorobenzenesulfonimide
Authors: Liu Yongan , Wu Hao , Guo Yong , Xiao Ji‐Chang , Chen Qing‐Yun , Liu Chao
Published: November 2017

Presented is a novel intermolecular radical trifluoromethylfluorosulfonylation of unactivated alkenes under mild reaction conditions with good functional‐group tolerance in the most atom‐economic manner by using readily available Ag(O2CCF2SO2F) and N‐fluorobenzenesulfonimide (NFSI). Both the trifluoromethyl and sulfonyl groups in the products originate from Ag(O2CCF2SO2F).
Trockenbausystem aus Carbonbeton
Authors: Dinkelaker Max , Michel Albert , Schladitz Frank , Aurbach Stefanie
Published: November 2017

Im Rahmen der Carbonbetonentwicklung steht oft die Frage im Raum: „In welchen Bereichen kann man das Anwendungsfeld des Carbonbetons erweitern?“ Die vorliegende Veröffentlichung zeigt die mögliche Anwendung des Carbonbetons im Trockenbausystem. Nach einer ersten Begriffsdefinition wird allgemein auf Trockenbausysteme eingegangen. Davon abgeleitet wird die Anwendung von Carbonbeton in diesem Bereich. Erste vielversprechende Ergebnisse aus Berechnungen, Experimenten und Praxistests werden präsentiert.
Athenolide A, a New Steroidal Lactone from the Leaves of Athenaea martiana (Solanaceae) Determined by Means of HPLC‐HR‐MS‐SPE‐NMR Analysis
Authors: Silva Eder L. , Almeida‐Lafetá Rita C. , Borges Ricardo M. , Staerk Dan
Published: November 2017

Athenaea (Solanaceae) is an endemic genus belonging to the Brazilian Atlantic Rainforest. Recently, botanical investigations suggested the re‐evaluation of the generic status of the genus Athenaea as a synonym of Aureliana. In this study, the first investigation of the Athenaea genus performed on Athenaea martiana by means of HPLC‐HR‐MS‐SPE‐NMR combined with high‐resolution radical scavenging profile led to identification of several phenolic acids as radical scavengers: protocatechuic acid (1), 4‐hydroxybenzoic acid (2), caffeic acid (3), vanillic acid (4), and ferulic acid (6). Additional analysis revealed a new steroidal lactone, named athenolide A (9). Their structures were elucidated by extensive use of NMR spectroscopy as well as HR‐MS. Chemotaxonomic considerations based on these results supported the chemical relationships between the Athenaea and Aureliana genera, in agreement with the recent botanical findings.
Uptake of home dialysis in younger adults: case studies that illustrate the multifaceted influence of home circumstances on dialysis decisions
Authors: Collingridge Louise , Equinox Keri‐Lu , Frasca Serena , Simmonds Rosemary , Tomlins Melinda , Chow Josephine
Published: November 2017

Key Clinical Message

Younger adults considering home dialysis need support to ensure home circumstances are suitable and affordable. Home circumstances relate closely to the financial burden reported by younger home dialysis users. Attention to home circumstances of younger patients with chronic kidney disease by policymakers, funders, and healthcare practitioners is needed.
Calculation Approach for Ceramic Heat Pipe‐Heat Exchanger for High‐Temperature Applications
Authors: Unz Simon , Hack Nina , Beckmann Michael
Published: November 2017

Metallische Werkstoffe weisen bei hohen Temperaturen und chemisch aggressiven Atmosphären geringe Standzeiten auf. Eine Alternative sind keramische Werkstoffe, die jedoch nicht wie metallische Werkstoffe verarbeitet werden können. Deshalb wird der Einsatz einer einfachen Wärmerohrgeometrie als Grundform für Wärmeübertragungssysteme in der Hochtemperaturtechnik betrachtet. Zur Auslegung von Hochtemperaturwärmeübertragern wird ein numerisches Berechnungsmodell zur genauen Bestimmung des Betriebsverhaltens großer Apparate vorgestellt, das neben konvektivem auch den strahlungsabhängigen Wärmetransport berücksichtigt.
Sicherer Umgang mit Kanülen – von Erfahrungen zu Evidenzen
Authors: Sieve Bernhard F. , Taubert Christin , Taubert Richard
Published: November 2017

Medizintechnische Geräte gehören mittlerweile an vielen Schulen zum experimentellen Repertoire. Von den dabei verwendeten spitzen Kanülen geht jedoch ein nicht zu vernachlässigendes Verletzungsrisiko aus, weshalb in der Experimentierliteratur verschiedene und allesamt auf persönlichen Erfahrungen beruhende Empfehlungen zur „Entschärfung“ von Kanülen existieren. In diesem Beitrag werden die Ergebnisse einer reproduzierbaren Testung des Gefährdungspotentials von auf verschiedene Weise abgestumpften Kanülen in Bezug auf Stich‐ und Schnitt‐ bzw. Rissverletzungen vorgestellt. Aus den Ergebnissen werden evidenzbasierte Empfehlungen für die Nutzung von Kanülen im Chemieunterricht abgeleitet.
Untersuchungen zum Silber‐Zink‐Akkumulator
Authors: Jakob Birgit , Habekost Achim
Published: November 2017

Der Silber‐Zink Akku ist ein recht teurer Akkumulator mit zudem geringer Lebensdauer, er besitzt aber eine sehr hohe Kapazität bei geringem Volumen und Gewicht. Die Leerlaufspannung einer Zelle beträgt 1,5 Volt. Der Akku spielt wegen seiner Robustheit vor allem bei der Marine und in der Raumfahrt eine große Rolle. Auch aus didaktischen Gründen ist der Silber‐Zink Akku interessant, denn die Änderungen an der Silberelektrode sind gut optisch zu beobachten und messtechnisch mit einfachen Mitteln zu verfolgen. Zudem sind die Elektrodenvorgänge intensiv untersucht worden und gut verstanden und daher eindeutig beschreibbar.
Der Einsatz von Modellen zum Erkenntnisgewinn / Eine Unterrichtseinheit zur Förderung der Modellkompetenz im Kontext „Batterie“ unter explizitem Einbezug von Schülervorstellungen
Authors: Caspari Ira , Weber‐Peukert Gisela , Graulich Nicole
Published: November 2017

Die Modellkompetenz bedarf als Standbein der Erkenntnisgewinnung einer gezielten Förderung im naturwissenschaftlichen Unterricht. Angelehnt an ein Modell der Modellkompetenz aus der Biologiedidaktik liefert die hier skizzierte Unterrichtskonzeption ein praxiserprobtes Beispiel, wie dies im Chemieunterricht umgesetzt werden kann. Ausgehend von phänomenologischen Betrachtungen des Leitungsmechanismus im Elektrolyten und der chemischen Abläufe in handelsüblichen Batterien entwickeln Lernende eigene Modelle, denen alternative Schülervorstellungen und ‐konzepte zugrunde liegen. Darauf basierend stellen die Lernenden Hypothesen über das jeweilige Original auf. Durch das experimentelle Überprüfen können schülereigene Hypothesen und Modelle und gleichzeitig die zugrunde liegenden Vorstellungen bestätigt oder falsifiziert und geändert werden. So gelingt es in dieser Unterrichtskonzeption, die Förderung der Modellkompetenz und den Umgang mit Schülervorstellungen lernförderlich zu kombinieren.
E‐Diazocine in Chemical Education: Synthesis, Structure, Photochromism and Thermal Stability
Authors: Krämer René , Nöthling Nils , Lehmann Christian W. , Mohr Fabian , Tausch Michael W.
Published: November 2017

Z‐diazocine, synthesized as described by Tellkamp, has been photochemically converted into E‐diazocine by irradiation of its solution at λ=365 nm. After purification, single crystals of E‐diazocine were obtained by recrystallization at −18 °C from n‐pentane. The title compound was characterized by NMR spectroscopy and X‐ray crystallography. For its thermal isomerization into the more stable Z‐isomer, the thermal half‐life was determined by UV/Vis absorption studies. Furthermore, the photochemical behaviour of the compound in the solid state has been investigated.
Effects of Surface Tension Driven Convection Upon Crystal Growth of KTa1‐xNbxO3
Authors: Li Shuhui , Pan Xiuhong , Liu Yan , Jin Weiqing , Zhang Minghui , Gai Lijun , Lei Lei , Deng Weijie , Chen Kun
Published: November 2017

The surface tension driven convection, together with the rotating crystal growth process of potassium tantalate niobate (KTa1‐xNbxO3, KTN) crystals from unstirred melt has been carried out in a high temperature in‐situ observation system. The streamline of the stable convection is found to be in the form of a double loop axially symmetric vortices, which causes the rotation during KTN crystals growth process. The effect of surface tension convection on interfacial heat, mass and momentum transfer are investigated experimentally. The dimensionless parameters of the three transports are calculated. For KTN crystals, velocity and temperature boundary layers are pointless. Solute transfer is the main form of interface transport during crystal growth process. The effect of Nb content x on boundary layer thickness is discussed. There is a critical Marangoni Number . When , the concentration boundary layer becomes thinner with the increase of x as a result of weakened segregation effect. When , a thicker boundary layer emerges due to slower growth velocity under higher Nb contents. When , the influence of the two is comparable and the boundary layer can maintain a relatively steady value under different components.
Hydrogen Evolution by FeIII Molecular Electrocatalysts Interconverting between Mono and Di‐Nuclear Structures in Aqueous Phase
Authors: Tagliapietra Mirko , Squarcina Andrea , Hickey Neal , De Zorzi Rita , Geremia Silvano , Sartorel Andrea , Bonchio Marcella
Published: November 2017

A new FeL/Fe2L2 manifold, with HL=2‐({[di(2‐pyridyl)methyl](methyl)amino}methyl)phenol, was prepared in gram scale (>50 % yield) and characterized in solution and solid state. The monomer/dimer interconversion is controlled in aqueous phase, upon varying the pH conditions. The electrocatalytic hydrogen evolution reaction (HER) occurs through the FeL monomer with added trifluoroacetic acid (TFA) and through the Fe2L2 μ‐oxo dimer in acetate buffer (pH 4.9), with an overpotential of about 1 V and faradaic yield up to 75 %. The resulting icat/ip values in the range 15–28 are among the highest reported for Fe‐based electrocatalysts (icat is the catalytic current, whereas ip is the current of an Fe‐based redox event).
1,8‐Naphthyridinecarbaldehydes and Their Methyl‐Substituted Precursors: Synthesis, Molecular Structures, Supramolecular Motifs and Trapped Water Clusters
Authors: Rosin Robert , Seichter Wilhelm , Schwarzer Anke , Mazik Monika
Published: November 2017

1,8‐Naphthyridinecarbaldehydes bearing chlorine, pyrrolidinyl, piperidinyl or morpholinyl groups, were synthesised by oxidation of their methyl‐substituted precursors. The prepared carbaldehydes represent valuable starting materials for the construction of systems that are useful for supramolecular and medicinal chemistry. Single‐crystal X‐ray diffraction studies of four carbaldehydes and six methyl derivatives provided interesting information about the supramolecular motifs in the crystal structures of solvent‐free and solvated naphthyridines. The formation of interesting water clusters, for example, T4(2) water tape, was observed in the case of 7‐methyl‐2‐(piperidin‐1‐yl)‐1,8‐naphthyridine as well as in the crystal structure of a by‐product 7‐(morpholin‐1‐yl)‐1,8‐naphthyridine‐2‐carboxylic acid. Knowledge of the detailed structural properties of water clusters is of great research interest to a broad range of scientific disciplines.
Initial Application of Selected‐Ion Flow‐Tube Mass Spectrometry to Real‐Time Product Detection in Electrochemical CO2 Reduction
Authors: Lobaccaro Peter , Mandal Lily , Motapothula Mallikarjuna Rao , Sherburne Matthew , Martin Jens , Venkatesan T. , Ager Joel W.
Published: November 2017

Electrochemical CO2 reduction (EC‐CO2R) has seen a resurgence in interest over the past several years; however, the means of analyzing catalytically produced products continues to rely on decades‐old methods such as gas chromatography, high‐performance liquid chromatography, and nuclear magnetic resonance. Real‐time analysis of the gaseous and liquid products of this reaction is highly desirable; however, few analytical techniques have been developed thus far to meet this need. Here, we demonstrate the first use of selected‐ion flow‐tube mass spectrometry (SIFT‐MS) as an analytical tool capable of measuring in real time both the gas‐ and liquid‐phase products of EC‐CO2R in aqueous solution. SIFT‐MS uses well‐understood ion–molecule reactions to enable the analysis of similar multicomponent mixtures by preventing substantial fragmentation of the analyte. We lay out the framework in which to evaluate the tool's capabilities and show that the C1–C3 hydrocarbon, alcohol, and aldehyde products of CO2R should be quantitatively detectable.
Phenotypic responses in Caenorhabditis elegans following chronic low-level exposures to inorganic and organic compounds
Authors: Mugova Fidelis , Read Daniel S. , Riding Matthew J. , Martin Francis L. , Tyne William , Svendsen Claus , Spurgeon David
Published: November 2017

Responses of organisms to sublethal exposure of environmental stressors can be difficult to detect. We investigated phenotypic changes in the tissue of Caenorhabditis elegans via Raman spectroscopy, as well as survival and reproductive output when exposed to chronic low doses of metals (copper, zinc, or silver), an herbicide (diuron), and a pesticide (imidacloprid). Raman spectroscopy measures changes in phenotype by providing information about the molecular composition and relative abundance of biomolecules. Multivariate analysis was used to evaluate the significance of treatment phenotype segregation plots compared with controls. Dose-dependent responses were observed for copper, zinc, silver, and diuron, whereas imidacloprid exposure resulted in a small response over the tested concentrations. Concentration-dependent shifts in nematode biomolecular phenotype were observed for copper. Despite having a dose–dependent reproductive response, silver, diuron, and imidacloprid produced inconsistent biological phenotype patterns. In contrast, there was a clear stepwise change between low concentrations (0.00625–0.5 mg/L) and higher concentration (1–2 mg/L) of ionic zinc. The findings demonstrate that measuring phenotypic responses via Raman spectroscopy can provide insights into the biomolecular mechanisms of toxicity. Despite the lack of consistency between survival and Raman-measured phenotypic changes, the results support the effectiveness of Raman spectroscopy and multivariate analysis to detect sublethal responses of chemicals in whole organisms and to identify toxic effect thresholds. Environ Toxicol Chem 2018;37:920–930. © 2017 SETAC
Systematic review and meta‐analysis of the performance of second‐trimester screening for prenatal detection of congenital heart defects
Authors: van Velzen Christine L. , Ket Johannes C.F. , van de Ven Peter M. , Blom Nico A. , Haak Monique C.
Published: November 2017

Background

The prenatal detection rate of congenital heart defects (CHDs) is increasing, but reported rates vary.

Objectives

To determine the performance of the second‐trimester anomaly scan to detect CHD.

Search strategy

PubMed and Embase were searched for relevant studies in any language from inception to February 3, 2017. The search terms included “prenatal diagnosis” or “pregnancy,” “cardiovascular diseases” or “cardiac defects,” “congenital,” and “specificity,” or “sensitivity,” or “cohort study.”

Selection criteria

Cohort studies assessing the detection rate of CHD during population‐based prenatal screening from 1995 were eligible for inclusion.

Data collection and analysis

Data were collected from identified studies; authors were approached for additional data when necessary. A review and meta‐analysis were performed. When possible, separate analyses were undertaken for isolated CHD cases.

Main results

Meta‐analysis of seven studies showed the pooled detection rate of CHD in unselected populations as 45.1% (95% confidence interval 33.5%–57.0%). However, the rate of detection of univentricular defects and heterotaxy was above 85%. Similar rates were found among cases of isolated CHD.

Conclusions

Prenatal detection showed a strong correlation with CHD severity. The detection of conotruncal anomalies needs to improve. A thoroughly organized screening program will be essential to achieve a higher detection rate.
Post‐Ebola situational assessment of opportunities for capacity building at the national obstetrics and gynecology referral hospital in Sierra Leone
Authors: Chan Seay Rachel , Koroma Alimamy P. , Coleman Jenell , Sampson John , Koroma Lucy , Ugwa Emmanuel A. , Anderson Jean
Published: November 2017

Objective

To describe a site assessment of the Princess Christian Maternity Hospital (PCMH; Freetown, Sierra Leone), the national referral center for reproductive, maternal, newborn, child and adolescent health (RMNCAH) services and logical site for focused efforts to train and expand the RMNCAH workforce in Sierra Leone.

Methods

In April 2016, a mixed‐methods assessment approach was used involving facility observation and staff interviews using the WHO's Service Availability and Readiness Assessment (SARA) tool. Quantitative and qualitative data were obtained.

Results

PCMH had 150 inpatient beds and provided care for more than 4600 deliveries in 2015. The number of maternal deaths increased at a rate of approximately 40% per month from January 2015 to June 2016 (P=0.005). Key factors requiring attention were identified in the categories of infrastructure and supplies, RMNCAH services, and human resources.

Conclusion

SARA provided a framework for identifying strengths and weaknesses in infrastructure and supplies, RMNCAH services, and human resources. The process described might serve as a model for evaluating obstetrics and gynecology training facilities in low‐ and middle‐income countries. Human resources are currently insufficient for the volume and complexity of patients at PCMH. Numerous opportunities exist for strengthening healthcare services and capacity building in Sierra Leone.
Positive discipline, harsh physical discipline, physical discipline and psychological aggression in five Caribbean countries: Associations with preschoolers' early literacy skills
Authors: Dede Yildirim Elif , Roopnarine Jaipaul L.
Published: November 2017

Physical punishment has received worldwide attention because of its negative impact on children's cognitive and social development and its implications for children's rights. Using UNICEF Multiple Indicator Cluster Surveys 4 and 5 data, we assessed the associations between positive discipline, harsh physical punishment, physical punishment and psychological aggression and preschoolers' literacy skills in 5628 preschool‐aged children and their caregivers in the developing nations of Belize, the Dominican Republic, Guyana, Jamaica and Suriname. Caregivers across countries used high levels of explanations and psychological aggression. There were significant country differences in the use of the four disciplinary practices. In the Dominican Republic and Guyana, physical punishment had negative associations with children's literacy skills, and in the Dominican Republic, positive discipline had a positive association with children's literacy skills. Findings are discussed with respect to the negative consequences of harsh disciplinary practices on preschoolers' early literacy skills in the developing world.
Sadness and ruminative thinking independently depress people's moods
Authors: Jahanitabesh Azra , Cardwell Brittany A. , Halberstadt Jamin
Published: November 2017

Depression and rumination often co‐occur in clinical populations, but it is not clear which causes which, or if both are manifestations of an underlying pathology. Does rumination simply exacerbate whatever affect a person is experiencing, or is it a negative experience in and of itself? In two experiments we answer this question by independently manipulating emotion and rumination. Participants were allocated to sad or neutral (in Experiment 1), or sad, neutral or happy (Experiment 2) mood conditions, via a combination of emotionally evocative music and autobiographical recall. Afterwards, in both studies, participants either ruminated by thinking about self‐relevant statements or, in a control group, thought about self‐irrelevant statements. Taken together, our data show that, independent of participants' mood, ruminators reported more negative affect relative to controls. The findings are consistent with theories suggesting that self‐focus is itself unpleasant, and illustrate that depressive rumination comprises both affective and ruminative components, which could be targeted independently in clinical samples.
Hydrogel/fiber conductive scaffold for bone tissue engineering
Authors: Khorshidi Sajedeh , Karkhaneh Akbar
Published: November 2017

Hydrogel/fiber composites have emerged as compelling scaffolds for regeneration purposes. Any biorelated modification or feature may endow more regenerative functionality to these composites. In the present study, a hydrogel/fiber scaffold possessing electrical conductivity in both phases, hydrogel and fiber, has been prepared and evaluated. Fiber component possessed electrical conductivity due to the presence of polyaniline (PANi) and hydrogel fraction thanks to the presence of graphene nanoparticles. PANi based fibers were processed through electrospinning and transformed into a three‐dimensional structure through ultrasonication. The hydrogel precursor solution composed of oxidized polysaccharides, gelatin and graphene with predesigned ratio was added to fibers and left to gel. The results of assessments on pristine hydrogel and hydrogel/fiber denoted that inclusion of conducting fibers into hydrogel increased elastic modulus, roughness and electrical conductivity, whereas decreased hydrophilicity. Moreover, the results showed that hydrogel/fiber composite better supported human osteoblast‐like cell adhesion, proliferation, and morphology comparing hydrogel alone. In a nutshell, the presence of gel/fiber architecture along with electrical conductivity may lead the scaffold to be very promising for bone regeneration. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 718–724, 2018.
Atomic force microscopy and nanoindentation investigation of polydimethylsiloxane elastomeric substrate compliancy for various sputtered thin film morphologies
Authors: Maji Debashis , Das Soumen
Published: November 2017

Crack free electrically continuous metal thin films over soft elastomeric substrates play an integral part in realization of modern day flexible bioelectronics and biosensors. Under nonoptimized deposition conditions, delamination, and/or cracking of the top film as well as the underlying soft substrate hinders optimal performance of these devices. Hence it is very important to understand and control not only the various deposition factors like power, time, or deposition pressure but also investigate the various interfacial physics playing a critical role in assuring thin film adhesion and substrate compliancy. In the present study, various nanomechanical information of the underlying substrate, namely, crack profile, average roughness, Young's modulus, and adhesion force were studied for uncracked and cracked polydimethylsiloxane (PDMS) surfaces along with pristine and conventional plasma treated PDMS samples as control. Quantification of the above parameters were done using three‐dimensional surface profiler, scanning electron microscopy, nanoindentation, and atomic force microscopy techniques to elucidate the modulus range, average roughness, and adhesion force. Comparative analysis with control revealed remarkable similarity between increased modulus values, increased surface roughness, and reduced adhesion force accounting for reduced substrate compliancy and resulting in film cracking or buckling which are critical for development of various bioflexible devices. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 725–737, 2018.
Absorbable mineral nanocomposite for biomedical applications: Influence of homogenous fiber dispersity on mechanical properties
Authors: Mulky Elias , Maniura‐Weber Katharina , Frenz Martin , Fortunato Giuseppino , Luginbuehl Reto
Published: November 2017

Electrospun micro‐ and nanosized fibers are frequently used as reinforcing elements in low temperature ceramic composites for biomedical applications. Electrospinning of fibers yield, however, not individual fibers, but rather fiber‐mats that are difficult to separate. Most investigations have been performed on diced mats and highly nonhomogenous composites. We examined the influence of dispersed electrospun single micro‐ and nanometer fibers on the mechanical properties of calcium phosphate cement composites. Absorbable poly‐l‐lactic‐acid was electrospun yielding fibers with diameters of 244 ± 78 nm, named nanofibers (NF), and 1.0 ± 0.3 μm, named microfibers (MF). These fibers were cut using a particle assisted ultrasonication process and dispersed with hydroxyapatite nanoparticles and composites of low (5%) and high (30%) NF/MF content were engineered. The homogeneity of the fiber distribution was investigated by analyzing fracture areas regarding the number of fibers and Voronoi area size distribution. Variation of fiber distribution was significantly lower in the NF group as compared to the MF group. For composites containing 5% NF (V/V), an eightfold increase in the compressive fracture strength, and for the 30% NF (V/V) a threefold increase compared was measured. The composite containing 5% NF was identified as optimal regarding fiber distribution and strength. Our new method of engineering these composites allows for high volume fractions of NF with low variation in fiber distribution to be incorporated into composites, and shows the importance of using single filaments as reinforcing agents. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 850–857, 2018.
Baseline response rates affect resistance to change
Authors: Kuroda Toshikazu , Cook James E. , Lattal Kennon A.
Published: November 2017

The effect of response rates on resistance to change, measured as resistance to extinction, was examined in two experiments. In Experiment 1, responding in transition from a variable‐ratio schedule and its yoked‐interval counterpart to extinction was compared with pigeons. Following training on a multiple variable‐ratio yoked‐interval schedule of reinforcement, in which response rates were higher in the former component, reinforcement was removed from both components during a single extended extinction session. Resistance to extinction in the yoked‐interval component was always either greater or equal to that in the variable‐ratio component. In Experiment 2, resistance to extinction was compared for two groups of rats that exhibited either high or low response rates when maintained on identical variable‐interval schedules. Resistance to extinction was greater for the lower‐response‐rate group. These results suggest that baseline response rate can contribute to resistance to change. Such effects, however, can only be revealed when baseline response rate and reinforcement rate are disentangled (Experiments 1 and 2) from the more usual circumstance where the two covary. Furthermore, they are more cleanly revealed when the programmed contingencies controlling high and low response rates are identical, as in Experiment 2.
Nitric oxide enhances selenium concentration by promoting selenite uptake by rice roots
Authors: Xiao Qiang , Li Xiu-Ling , Gao Gui-Feng , Chen Juan , Liu Xiang , Shen Zhi-Jun , Zhu Xue-Yi , Zheng Hai-Lei
Published: November 2017

Nitric oxide (NO) plays a key role in regulating a wide range of physiological and biochemical processes. This study investigated possible effects of NO, which was supplied by sodium nitroprusside (SNP), NO donor, on selenium (Se) concentration, Se species within roots, activities and gene transcription of selenite uptake, and metabolism‐related transporters or enzymes using ICP‐MS, HPLC‐ICP/MS, qRT‐PCR, fluorescence imaging, and biochemical analysis in the roots of rice (Oryza sativa L.) seedling. A suitable SNP concentration (10 µM) increased Se concentration in rice roots. NO enhanced the gene transcription of phosphate transporter OsPT2 and sulfate transporters OsSultr1;2 and OsSultr4;1 that contribute to selenite uptake. Furthermore, NO increased selenocysteine and methyl‐selenocysteine concentrations in roots, stimulated glutathione biosynthesis by up‐regulating the transcript levels of γ‐glutamylcysteine synthetase (γ‐ECS) and glutathione synthetase (GS), and increased cysteine synthase (CS) activity. In conclusion, our results indicate that NO promotes Se concentration of rice seedling roots by enhancing selenite uptake, up‐regulating gene transcription of selenite uptake‐related transporters, and increasing Se metabolism through regulating glutathione biosynthesis.
A case of quetiapine‐induced catatonia
Authors: Lucas Grace L. , Adewumi Adeleke D.
Published: November 2017

Aim

To present a case of catatonia on exposure to quetiapine.

Clinical details

We report the case of a 68‐year‐old man with bipolar affective disorder who experienced catatonia upon initiation of quetiapine on day 4 of his admission to hospital. He was commenced on quetiapine 50 mg at night which was increased to 100 mg the following night. He did not have a prior history of any reaction to the medication.

Outcome symptoms

Resolved upon discontinuation of quetiapine.

Conclusion

The importance of pharmacovigilance cannot be overemphasised. Clinicians need to be aware that catatonia may occur with the use of quetiapine and patients need to be closely monitored for unexpected reactions.
Online Detection of Functional Groups in SEC via Quantum Cascade Laser IR Spectroscopy
Authors: Morlock Sascha , Kübel Jennifer M. , Beskers Timo F. , Lendl Bernhard , Wilhelm Manfred
Published: November 2017

The development of coupled techniques based on chemically sensitive detectors, such as FTIR or NMR spectrometers, for size exclusion chromatography (SEC) provides sophisticated methods for determining the molecular‐weight‐dependent chemical composition in polymers. However, the detection of rare functionalities such as end groups or branching points presents a challenge, especially for online coupled SEC detection, which is based on low‐concentration chromatography. To address this issue, for the first time, an external cavity quantum cascade laser (EC‐QCL) infrared spectrometer is coupled to an SEC. The system is evaluated using polystyrene/poly(methyl methacrylate) (PS/PMMA) blends. The current limit of detection for the carbonyl (PMMA) stretch vibration at 1730 cm−1 with this technique is 3.5 µg PMMA on a semipreparative column (typical load of 2.5 mg polymer in total). That equals 0.15 mol% of PMMA in the PS/PMMA blend and corresponds to one carbonyl group per 70 kg mol−1 polymer.
Patient with Hemiparkinsonism Secondary to a Gun Pellet in the Contralateral Substantia Nigra
Authors: Shalash Ali , Abushady Eman , Hamid Eman , Salama Mohamed , Ibrahim Yosra Abdelzaher
Published: November 2017

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Detecting the persistence of drying trends under changing climate conditions using four meteorological drought indices
Authors: Khan Muhammad Imran , Liu Dong , Fu Qiang , Faiz Muhammad Abrar
Published: November 2017

Numerous drought indices based on single or multiple variables have been developed for the assessment of drought. This study aimed to detect the variability of droughts by applying four drought indices, the standardized precipitation index, the reconnaissance drought index, the standardized precipitation evaporative drought index and the effective drought index, at five meteorological stations in the Songhua River basin (SRB) in China during 1962–2013 and at two meteorological stations in the Indus River basin (IRB) during 1980–2013 using different timescales (3, 6, 9 and 12 months). Moreover, a Mann−Kendall trend test at the 5% significance level was used for the assessment of drought trends in the basins. The results indicated that the 12 month data series for the SRB and the 6 month data series for the IRB were appropriate for assessing dry conditions and for comparing the drought indices. Pearson's correlation analyses between the drought indices results and the meteorological variables revealed that the standardized precipitation index is a better drought index for the assessment of drought in the SRB (r = 0.99). The results also showed that the standardized precipitation evaporative drought index versus the reconnaissance drought index is better at identifying drought in the IRB with a Pearson's correlation value r of 0.98. Severe and extremely dry conditions prevailed between 1990 and 2001 in the SRB, and there were extreme drought conditions with an intensity of −2.00 in the IRB during 2001–2002. Overall, this study provides insights into choosing the appropriate time interval and drought index for a specific region to identify the severity of droughts.
Generative Recurrent Networks for De Novo Drug Design
Authors: Gupta Anvita , Müller Alex T. , Huisman Berend J. H. , Fuchs Jens A. , Schneider Petra , Schneider Gisbert
Published: November 2017

Generative artificial intelligence models present a fresh approach to chemogenomics and de novo drug design, as they provide researchers with the ability to narrow down their search of the chemical space and focus on regions of interest. We present a method for molecular de novo design that utilizes generative recurrent neural networks (RNN) containing long short‐term memory (LSTM) cells. This computational model captured the syntax of molecular representation in terms of SMILES strings with close to perfect accuracy. The learned pattern probabilities can be used for de novo SMILES generation. This molecular design concept eliminates the need for virtual compound library enumeration. By employing transfer learning, we fine‐tuned the RNN′s predictions for specific molecular targets. This approach enables virtual compound design without requiring secondary or external activity prediction, which could introduce error or unwanted bias. The results obtained advocate this generative RNN‐LSTM system for high‐impact use cases, such as low‐data drug discovery, fragment based molecular design, and hit‐to‐lead optimization for diverse drug targets.
Dynamic collimator trajectory algorithm for multiple metastases dynamic conformal arc treatment planning
Authors: MacDonald R. Lee , Thomas Christopher G. , Syme Alasdair
Published: November 2017

Purpose

To develop an algorithm for dynamic collimator positioning to optimize beam's eye view (BEV) fitting of targets in dynamic conformal arc (DCA)‐based radiotherapy procedures, of particular use in multiple metastases stereotactic radiosurgery procedures.

Methods

A trajectory algorithm was developed to dynamically modify the angle of the collimator as a function of arc‐based control point to provide optimized collimation of target volume(s). Central to this algorithm is a concept denoted herein as “whitespace” defined as any nontarget area in the BEV that is not covered by any collimation system and is open to exposure from the radiation beam. Calculating whitespace at all collimator angles and every control point, a two‐dimensional topographical map depicting the tightness‐of‐fit of the MLC was generated. A bidirectional gradient trajectory algorithm identified a number of candidate trajectories of continuous collimator motion. Minimization of integrated whitespace was used to identify an optimal solution for the navigation of the parameter space. Plans with dynamic collimator trajectories were designed for multiple metastases targets and were compared with fixed collimator angle dynamic conformal arc (DCA) plans and standard VMAT plans.

Results

Algorithm validation was performed on simple test cases with known solutions. The whitespace metric showed a strong correlation (R2 = 0.90) with mean dose to proximal normal tissue. Seventeen cases were studied using our algorithm to generate dynamic conformal arc (DCA) plans with optimized collimator trajectories for three and four target SRS patients and comparing them to DCA plans generated with optimized fixed collimator angles per arc and standard VMAT plans generated via template. Optimized collimator trajectories were found to produce a reduction in monitor units of up to 49.7 ± 5.1% when compared to VMAT across 17 patients, and all organ‐at‐risk and normal brain metrics were found to be superior or comparable.

Conclusion

Dynamic collimator trajectories have the potential to improve DCA deliveries through increased efficiency, especially in the treatment of multiple cranial metastases. Implementation of this technology should not be hindered by mechanical safety considerations as collimator motions do not modify or introduce any new risks of collisions with patients.