bluuebunny/crossref_metadata_2025 huggingface dataset:
SYNTHESIS AND STUDY OF PROPERTIES OF SURFACTANTS BASED ON FAT ACIDS OF PALM OIL AND METHANOL
Authors: Lutfullina Gulnaz G. , Guseva Ksenia S. , Grishin Pavel V. , Khairutdinova Razikya K.
Published: June 2018

A new product was obtained with the use of methyl alcohol and fatty acids of palm oil. The series of experimens were performed to reveal its composition and properties with the use of modern devices and methods. The results of IR-spectroscopy have approved the presence of specific functional groups: hydroxylic, ester, carboxylic and sulfonate ones. The results of studies have shown that the synthesized substance posesses the surfactant properties: wetting, foaming, detersive; and it has a relatively low surface energy. It belongs to the group of high-despersity and mono-dispersity systems and takes an intermediate position between micro- and nano-particles. It was shown, that the contact angle of the water solution of the surfactant under study equals to at least 90 degrees and practically does not depend on the nature of wetted surface (eather hydrophylic or hydrofobic). It was founded that the foam expansion ratio and its stability are high and lay in direct relation with the substance concentration. It was found that relating to the protein composition, the detergent power of the surfactant is higher (up to 90 %) than regarding to pigment-and-oil contamination. Measuring the values of surface tension by Willhelm plate-bearing method allowed defining the critical concentration of micelle formation of 4.0 g/dm3, at which the maximum wetting is achieved. It was found that the synthezised product have a low emulsifying power towards the motor, machine oil and animal fat. Besides, the highest stability of emulsion was observed towards the machine oil (at concentration of synthesized product of 2.0 g/dm3). The emulsion stability can be increased by making compositions including the non-ionogenic surfactants. Moreover, it was found that the product under study is characterized by the high aggregative stability, since the achieved values of zeta-potential are in the range of 30 mB< ζ < -30 mB. The developed product belongs to the anionic surfactants, with рН of water solution of 7-8. It has a good water solubility. According to results of the hydrophylic-and-lipophylic balance, the synthesyzed surfactant belongs to detergents.Forcitation:Lutfullina G.G., Guseva K.S., Grishin P.B., Khairutdinova R.I. Synthesis and study of properties of surfactants based on fat acids of palm oil and methanol. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 6. P. 88-95
Anvendelsesforpligtet grundforskning på læreruddannelsen
Authors: Nielson Bo
Published: June 2018

Siden 2013 har læreruddannelsen fået pligt til at bedrive forskning og udvikling (FoU) som en del af kerneopgaven. Denne opgave er blevet implementeret på meget forskellige måder på landets læreruddannelser. I denne artikel argumenterer jeg for, at FoU skal balancere et ideal om transformation af praksis gennem udfordringsbasering og løsningsorientering, samtidig med at der skal ydes et substantielt bidrag til forskningsfeltet. FoU skal ligeledes balancere et ideal om praksisnærhed og medinddragelse samtidig med et ønske om generaliserbarhed og skalering. Artiklen afsluttes med en introduktion til interventionsforskningen som et konstruktivt bud på en ramme og struktur, der kan rumme ovenstående fordringer.  To be able to differentiate between approaches to teachers’ professional development, Cochran-Smith and Lytle have developed three conceptions of the relationships between teachers’ knowledge and their practice. One of these, Knowledge-of-practice, is the basis for this article, as we use Lesson studies to exemplify the potentials of approaches within this conceptualization. In Japan, Lesson studies are used in all subjects, whereas in the West the approach predominantly is used in Mathematics and with a focus on pedagogical content knowledge. Based on a lesson study case in the subject of Danish, we argue that approaches as lesson study provide teachers the possibility to research and solve teaching problems with a focus simultaneously on pedagogical knowledge and pedagogical content knowledge.
Automatic Detection And Calculation Of Drusen Areas In Retinal Fundus Fluorescein Angiography Images
Authors: DEMİR Önder , DOĞAN Buket , ÇALIK BAYEZİT Esra , YILDIZ Kazım
Published: June 2018

Computer aided detection (CAD) systems are widely
used in the analysis of biomedical images. In this paper, we present a novel
CAD system to detect age-related macular degeneration (ARMD) on retinal fundus
fluorescein angiography (FFA) images, and we provide an areal size calculation
of pathogenic drusen regions. The purpose of this study is to enable
identification and areal size calculation of ARMD-affected regions with the
developed CAD system; hence, we aim to discover the condition of the disease as
well as facilitate long-term patient follow-up treatment. With the aid of this
system, assessing the marked regions will take less time for ophthalmologists
and observing the progress of the treatment will be a simpler process. The CAD
system consists of four stages, a) preprocessing stage, b) segmentation stage,
c) region of interest detection and d)feature extraction stage and detection
stage. Detection through CAD and calculation of drusen regions were performed
with a dataset composed of 75 images. The results obtained from the developed
CAD system were examined by a specialist ophthalmologist, and the performance
criteria of the CAD system are reported as conclusions. As a result, with 66
correct detections and 9 incorrect detections, the developed CAD system
achieved an accuracy rate of 88%.
İndoksakarb Kalıntısı ve Bozunma Ürünü İçin Yeni Bir Tayin Yöntemi Geliştirilmesi
Authors: ÇUBUK Soner , AYDIN Adnan
Published: June 2018

Günümüze özellikle son 20 yıl süresince kullanımı çarpıcı bir şekilde artan pestisitler, modern tarımda böcekler, yabani otlar, mikroorganizmalar gibi zararlıları kontrol altına almak ve ürün verimini arttırmak için kullanılmakta olup hedef olmayan su, toprak ve gıdaları kirletmelerinin yanı sıra insan, evcil hayvanlar, bal arıları ve kuşlar için potansiyel sağlık riski gösterebilmektedirler. Zehirli olmalarının yanı sıra aynı zamanda bu bileşikler kanser yapıcı oluşumlara da sebep olurlar.  Böceklerin ve yabani otların bu kimyasallara olan dayanıklılığının artması sonucu dünya çapında pestisit kalıntı problemlerine yol açan daha fazla pestisit geliştirilmiş ve daha yüksek dozlarda kullanılmaya başlanmıştır. Bununla birlikte pestisitler, besin zincirine çeşitli yollarla girerek canlıların vücutlarında biyolojik birikime uğramakta ve bu besin zincirinde ilerlerken her aşamada daha büyük miktarlara erişmektedirler.Balın da arasında bulunduğu gıdalar başta olmak üzere birçok matristeki pestisitlerin analizinin yapılması canlıların ona ne oranda maruz kaldığının doğru bir şekilde değerlendirilmesi bakımından büyük bir önem arz etmektedir. Bu nedenle pestisitlere ait kalıntı seviyelerinin tespiti ve kullanılan metotların güncel mevzuatlarda yer alan tolere edilebilir kalıntı konsantrasyonları da kapsaması beklenmektedir. Son yıllarda bu alanda bazı çalışmalar yapılmış olmasına rağmen ülkemizde ballardaki pestisit tayinleriyle ilgili çok az çalışma bulunmaktadır.Çalışmamızda bal örneklerinde İndoksakarb ((S)-7-kloro-3-[meteksikarbonil-(4-trifluorometoksi-fenil)-karbamoil]-2,5-dihidro-indeno[1,2-e][1,3,4]oksadiazin-4a(3H)-karboksilik asit metil esteri) kalıntısının ve bozunma ürününün belirlenmesi için yeni bir yöntem geliştirilmiştir. Diklorometan ile ekstraksiyon sonrasında, Gaz Kromatograf-Kütle Spektrometresi kullanılarak indoksakarb ve bozunma ürününü tayin edilmiştir. Geliştirilen metota ait geri kazanım yüzdesi, tespit ve tayin sınırları sırasıyla %78,7±5,5 ; 0,03mg/kg ve 0,11mg/kg olarak hesaplanmıştır.İndoksakarbile kirletilmiş kestane, çiçek, çam ve ayçiçek balı numuneleri 3 farklı sıcaklıkta 8 ay süresince izlenmiş ve beşinci ayda 4-(trifluorometoksi)fenil izosiyanat,literatürde belirtilenlerden farklı bir bozunma ürünü olarak tespit edilmiştir.
Hypothesis of the conjunct expression gene: can random mutation explain the phenotypic variability?
Authors: Zapata Trejo Víctor A
Published: June 2018

If the environmental conditions can or not influence in the phenotype evolution, is a topic that has been discussed during the last ten years. The epigenome regulates the gene expression of all cells and indicates which specific genes must be transcribed. It is argued that the expression factors that act in specific genes of the somatic cells involved in a behavior also act in the partial transcription of the same genes in the most undifferentiated cells of the germ line. The functional role of the isochores as an epigenetic determinant regulator of the transcription and therefore of gene expression levels is discussed. It is proposed how a probabilistic view of the random mutation can integrate all the evidence pointing to a conjunct phenotype evolution with the environment. This work provides a new point of view on how the environment can influence in adaptation through natural selection considering the theory currently accepted.
Flexible Hybrid Electronic Material Systems with Programmable Strain Sensing Architectures
Authors: Sears Nicholas C. , Berrigan John Daniel , Buskohl Philip R. , Harne Ryan L.
Published: June 2018

Flexible hybrid electronics empower innovative electrical performance capabilities by maintaining electrical conductivity while undergoing large strains. Soft elastomeric material systems are also of great interest for means to control mechanical properties in ways unachievable by bulk materials. This work uncovers the synergy of flexible hybrid electronics and elastomeric material system concepts that becomes manifest by a strategic integration. Conductive silver microflake ink is applied to an elastomeric matrix composed with geometries that tune local strain distributions via microscopic geometries. The selection of internal beam geometries and placement of conductive ink traces are found to govern the strain transfer to the ink and hence the variation of electrical conductivity. Finite element simulations and experiments confirm the relationship between local constituent stretch and the overall material system conductivity. This relationship is exploited via two embodiments that have significant strain‐sensitivity or strain‐insensitivity. An extension of the concept reveals how both strain sensitivity and insensitivity may be leveraged by a single multifunctional, conductive material system. These results may motivate future concepts for strain sensors, shock isolators, biological monitoring equipment, and more.
Complex 3D‐Printed Microchannels within Cell‐Degradable Hydrogels
Authors: Song Kwang Hoon , Highley Christopher B. , Rouff Andrew , Burdick Jason A.
Published: June 2018

3D‐printing is emerging as a technology to introduce microchannels into hydrogels, for the perfusion of engineered constructs. Although numerous techniques have been developed, new techniques are still needed to obtain the complex geometries of blood vessels and with materials that permit desired cellular responses. Here, a printing process where a shear‐thinning and self‐healing hydrogel “ink” is injected directly into a “support” hydrogel with similar properties is reported. The support hydrogel is further engineered to undergo stabilization through a thiol‐ene reaction, permitting (i) the washing of the ink to produce microchannels and (ii) tunable properties depending on the crosslinker design. When adhesive peptides are included in the support hydrogel, endothelial cells form confluent monolayers within the channels, across a range of printed configurations (e.g., straight, stenosis, spiral). When protease‐degradable crosslinkers are used for the support hydrogel and gradients of angiogenic factors are introduced, endothelial cells sprout into the support hydrogel in the direction of the gradient. This printing approach is used to investigate the influence of channel curvature on angiogenic sprouting and increased sprouting is observed at curved locations. Ultimately, this technique can be used for a range of biomedical applications, from engineering vascularized tissue constructs to modeling in vitro cultures.
3D‐Ridge Stocked Layers of Nitrogen‐Doped Mesoporous Carbon Nanosheets for Ultrasensitive Monitoring of Dopamine Released from PC12 Cells under K+ Stimulation
Authors: Emran Mohammed Y. , Shenashen Mohamed A. , Morita Hiromi , El‐Safty Sherif A.
Published: June 2018

3D‐ridge nanosheets of N‐doped mesoporous carbon (NMCS)‐based electrodes are fabricated as ultrasensitive biosensors for in vitro monitoring of dopamine (DA) released from living cells. The large‐scale ranges of dense‐layered sheets are arranged linearly with a thickness of <10 nm, soft tangled edges, stocked layer arrangements, and tunable mesoporous frameworks with 3D orientations. The intrinsic features of the active interfacial surface of the electrode based on NMCS along with polarized surfaces, dense surface‐charged matrices, fast electron transfer, and easy molecular diffusion, are present in the highly active electrode for biosensing applications. The designed electrode based on the NMCS shows high sensitivity and selectivity for DA sensing even in the presence of physiological interference molecules, such as ascorbic acid and/or uric acid, at a low applied potential of 0.25 V versus Ag/AgCl. The large‐scale NMCS‐based electrode shows low detection limits as low as 10 nmol L−1, wide linear range up to 0.5 mmol L−1, long‐term stability for more than 15 d (relative standard deviation (RSD)= 5.8%), and a low cytotoxicity with high biocompatibility. The findings demonstrated that the NMCS‐based electrode is a reliable modified electrode for ultratrace sensitivity of DA, which is secreted normally from dopaminergic cells (PC12) or under a stimulating agent (K+).
Oxidative Radical Cyclization of N‐methyl‐N‐arylpropiolamide to Isatins via Cleavage of the Carbon‐carbon Triple Bond
Authors: Liao Yan‐Yan , Gao Yong‐Chao , Zheng Wenxu , Tang Ri‐Yuan
Published: June 2018

A radical cyclization of N‐methyl‐N‐arylpropiolamide to isatins via an oxidative cleavage of a carbon‐carbon triple bond has been developed. In the presence of oxone and NaNO2, a variety of N‐methyl‐N‐arylpropiolamides were smoothly transformed into isatins. A nitration reaction proceeded along with the oxidative cyclization; both nitrated and non‐nitrated isatins were obtained in a one‐pot reaction with moderate to good total yields. This is the first example for the synthesis of isatins via the oxidative radical cleavage of a carbon‐carbon triple bond.

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Aqueous Synthesis of Methylammonium Lead Halide Perovskite Nanocrystals
Authors: Geng Chong , Xu Shu , Zhong Haizheng , Rogach Andrey L. , Bi Wengang
Published: June 2018

Methylammonium lead halide perovskite nanocrystals offer attractive optoelectronic properties but suffer from fast degradation in the presence of water. In contradiction to this observation, we demonstrate the possibility of a direct aqueous synthesis of CH3NH3PbX3 (X=Br or Cl/Br) nanocrystals through the reaction between the lead halide complex and methylamine when the pH is maintained in the range of 0–5. Under these synthetic conditions, the positively charged surface of the perovskite nanocrystals and the proper ionic balance help to prevent their decomposition in water. Additional surface capping with organic amine ligands further improves the photoluminescence quantum yield of the perovskite nanocrystals to values close to 40 %, ensures their stability under ambient conditions for several months, and their photoluminescence performance under continuous 0.1 W mm−2 405 nm light irradiation for over 250 hours.
Boosting Size‐Selective Hydrogen Combustion in the Presence of Propene Using Controllable Metal Clusters Encapsulated in Zeolite
Authors: Shan Yuling , Sui Zhijun , Zhu Yian , Zhou Jinghong , Zhou Xinggui , Chen De
Published: June 2018

A strategy is presented for making metal clusters encapsulated inside microporous solids selectively accessible to reactant molecules by manipulating molecular sieve size and affinity for adsorbed molecules. This expands the catalytic capabilities of these materials to reactions demanding high selectivity and stability. Selective hydrogen combustion was achieved over Pt clusters encapsulated in LTA zeolite (KA, NaA, CaA) in a propene‐rich mixture obtained from propane dehydrogenation, showing pore‐size dependent selectivity and coking rate. Propene tended to adsorb at channels or external surfaces of zeolite, interfering the diffusion of hydrogen and oxygen. Tailoring the surface of LTA zeolite with additional alkali or alkaline earth oxides contributed to narrowing zeolite pore size and their affinity for propene. The thus‐modified Pt@KA catalyst displayed excellent hydrogen combustion selectivity (98.5 %) with high activity and superior anti‐coking and anti‐sintering properties.
Enantioseparation of Au20(PP3)4Cl4 Clusters with Intrinsically Chiral Cores
Authors: Zhu Yanfei , Wang Hui , Wan Kaiwei , Guo Jun , He Chunting , Yu Yue , Zhao Luyang , Zhang Yin , Lv Jiawei , Shi Lin , Jin Renxi , Zhang Xinxiang , Shi Xinghua , Tang Zhiyong
Published: June 2018

Au20(PP3)4Cl4 (PP3=tris(2‐(diphenylphosphino)ethyl) phosphine), abbreviated as Au20, is the only Au nanocluster with an intrinsically chiral core without a chiral environment (chiral ligands or Au‐thiolate staples), making it a unique object to understand chiral evolution and explore chiral applications. Unfortunately, the synthesized Au20 is racemic, and its enantiomers have not yet been separated. Herein, we report a supramolecular assembly strategy with α‐cyclodextrin (α‐CD) to afford enantiopure Au20 in bulk, and an enantiomer excess (ee) value of as‐separated Au20 of 97 %. As a result of its high purity, the distinctive optical activity of Au20, which originates from electronic transitions confined in chiral cores, is fully explored. Theoretical studies reveals that the enantioseparation results from the preferential self‐assembly of α‐CD with organic ligands on the surface of right‐handed Au20.
The returns to UK degrees for foreign‐educated graduates
Authors: Valbuena Javier , Zhu Yu
Published: June 2018

Exploiting information on foreign qualifications for the first time, we estimate the returns to obtaining UK higher degrees for foreign graduates who migrated to the UK in their 20s. Accounting for direct measures of foreign and UK qualifications and country‐of‐origin fixed effects, we find substantial returns to obtaining UK (higher) degrees on hourly wages and occupational attainment for both genders, working mainly through occupational attainment. However, there is strong evidence that the effect of the high returns is driven by immigrants from countries where English is not a dominant language. Moreover, returns to UK (higher) degrees are more pronounced for graduates from low‐HDI/GDP countries, suggesting an important role for the incompatibility of education and skills between home and destination countries. We further examine the robustness of our results by using a partial identification method, and our findings suggest that the extent of selection on unobservables required to eliminate a positive treatment effect is too large to be plausible, especially for men. Our study extends previous research with the first evidence from the UK, by showing large positive effects of post‐migration investments in human capital acquisition on labour market outcomes. Obtaining UK higher degrees appears to reduce the informational uncertainty associated with foreign credentials, facilitate cultural and economic assimilation, and boost economic opportunities for foreign graduates, especially for those developing/poor country immigrants.
Operational, interpersonal, discussional and ideational dimensions of classroom norms for dialogic practice in school mathematics
Authors: Hofmann Riikka , Ruthven Kenneth
Published: June 2018

While research suggests that interactive pedagogy drawing on students’ ideas can improve learning outcomes, it has been found difficult to change mathematics classroom practice in this direction. The reasons for this difficulty remain poorly understood, hindering change at scale. This article focuses on the under‐researched normative aspect of such practice which shapes participants’ actions and expectations. Drawing on theories of social practice and interaction, we define norms as recurrent and socially obligating patterns of, and rationales for, behaviour in a particular social practice. We then examine empirically what and how (new) norms associated with this type of pedagogy are manifest in classroom discursive activity by examining talk across 21 school mathematics lessons by 12 teachers implementing a dialogic intervention. While there is a clear distinction between surface norms and underlying rationales, and a consistent set of surface norms relating to classroom talk can be identified, deeper analysis finds norms to be multi‐dimensional. We illustrate how a surface norm, such as ‘Respect others’ ideas’, can be enunciated in terms of multiple underlying rationales which we term operational, interpersonal, discussional and ideational. Our findings shed new light on why the dialogic intentions of such interventions are often realised in a superficial way. We further examine the ways in which teachers hold students and themselves accountable to the ideational dimension—the dimension that relates to taking students’ ideas seriously in classroom dialogue.
Dietary Micronutrients Promote Neuronal Differentiation by Modulating the Mitochondrial‐Nuclear Dialogue
Authors: Xie Kui , Sheppard Allan
Published: June 2018

The metabolic requirements of differentiated neurons are significantly different from that of neuronal precursor and neural stem cells. While a re‐programming of metabolism is tightly coupled to the neuronal differentiation process, whether shifts in mitochondrial mass, glycolysis, and oxidative phosphorylation are required (or merely consequential) in differentiation is not yet certain. In addition to providing more energy, enhanced metabolism facilitates differentiation by supporting increased neurotransmitter signaling and underpinning epigenetic regulation of gene expression. Both epidemiological and animal studies demonstrate that micronutrients (MNs) significantly influence many aspects of neonatal brain development, particularly neural migration and survival, neurite outgrowth, and process maturation. Here we review recent insights into the importance of metabolic reprogramming in neuronal differentiation, before considering evidence that micronutrient signaling may be key to regulating these processes.
Wohin steuert die Taxonomie?
Authors: Kunz Werner
Published: June 2018

In der Taxonomie können die Organismen nach unterschiedlichen Kriterien zu Arten gruppiert werden, z.B. nach phänotypischen und genetischen Merkmalen oder nach der reproduktiven Verbindung. In der Natur gibt es nicht die universelle Einheit „Art“, weil unterschiedliche biologische Mechanismen dafür verantwortlich sind, wie die Individuen zu Gruppen zusammenhalten oder gegenseitig abgegrenzt werden. Unterschiedliche Artkonzepte definieren nicht unbedingt dieselbe in der Natur existierende Einheit. Ein und dasselbe Individuum kann je nach Artkonzept unterschiedlichen Arten zugeordnet werden. In den letzten zwei Jahrzehnten hat die Barcode‐Taxonomie eine dominierende Rolle eingenommen. Ein großer Vorteil der Barcode‐Taxonomie ist die zeitsparende maschinelle Massenerfassung von Arten, ohne dass dazu taxonomisch ausgebildete Experten erforderlich sind. Vor allem bei evolutionär jungen Arten kommt es aber zu erheblichen Diskrepanzen zwischen der Arteinteilung nach dem Barcode‐Konzept und der Einteilung nach Reproduktionsgemeinschaften oder nach phänotypischen Merkmalen. Die Barcode‐Art muss daher als eine Art neben anderen Artkonzepten verstanden werden.
A novel liquid chromatography Orbitrap mass spectrometry method with full scan for simultaneous determination of multiple bioactive constituents of Shenkang injection in rat tissues: Application to tissue distribution and pharmacokinetic studies
Authors: Yang Jie , Sun Zhi , Li Duolu , Duan Fei , Li Zhuolun , Lu Jingli , Shi Yingying , Xu Tanye , Zhang Xiaojian
Published: June 2018

Shenkang injection is a traditional Chinese formula with good curative effect on chronic renal failure. In this paper, a novel, rapid and sensitive ultra‐high‐performance liquid chromatography coupled with Q Exactive hybrid quadrupole Orbitrap high‐resolution accurate mass spectrometry was developed and validated for simultaneous determination of seven bioactive constituents of Shenkang injection in rat plasma and tissues after intravenous administration. Acetonitrile was used as a protein precipitation agent in biological samples disposal with carbamazepine as internal standard. The chromatographic separation was carried out on a C18column with a gradient mobile phase consisting of acetonitrile and water (containing 0.1% formic acid). The MS analysis was performed in the full‐scan positive and negative ion mode. The lower limits of quantification for the seven analytes in rat plasma and tissues were 0.1–10 ng/mL. The validated method was successfully applied to tissue distribution and pharmacokinetic studies of Shenkang injection after intravenous administration. The results of the tissue distribution study showed that the high concentrations of seven constituents were primarily in the kidney tract. This is the first report of the application of Q‐Orbitrap with full‐scan mass spectrometry in tissue distribution and pharmacokinetic studies of Shenkang injection.
The buffering role of in‐group identification and intergroup contact on the association between perceived discrimination and mental health
Authors: Bagci Sabahat C. , Turnuklu Abbas , Bekmezci Eyup
Published: June 2018

Previous research has shown that disadvantaged group members cope with the negative effects of perceived discrimination (PD) on mental health using various mechanisms. We examined the potential protective role of two processes—in‐group identification and intergroup contact—on the association between PD and mental health (anxiety and depression) among physically disabled adults (N = 269, Mage = 39.13, SD = 13.80). Intergroup contact, but not in‐group identification, had a buffering role on the association between PD and both depression and anxiety. However, this effect was further moderated by in‐group identification such that high levels of intergroup contact had a protective role against PD, only when in‐group identification was low. Findings highlight the importance of evaluating various social–psychological processes interactively in creating a resilient outlook among disadvantaged groups.
Mechanical and Crystallographic Analysis of Cholesterol Crystals Puncturing Biological Membranes
Authors: Al‐Handawi Marieh B. , Commins Patrick , Karothu Durga Prasad , Raj Gijo , Li Liang , Naumov Panče
Published: June 2018

Ischemic heart disease often leads to myocardial infarction and remains the most common cause for death in humans. Although the exact impetus for the infarction remains elusive, a mechanism has been proposed that relates the disease to the observed high cholesterol levels in the body. The mechanism claims that cholesterol crystallizes inside the arterial plaque into needle‐shaped crystals. The crystals puncture the fibrous cap of the plaque, whereby the necrotic contents of the plaque are spilled, subsequently clotting the blood vessels. This hypothesis has not been given sufficient attention partly due to the purported softness of the organic crystals and the common platy habit of the known crystal forms of cholesterol. In this work it is shown that, from hydrophobic solutions that attempt to emulate the plaque contents, a new solid form of cholesterol crystallizes as prisms with mucronate tips, and they are sufficiently strong to puncture a lamb pericardium, which mimics the plaque cap. The properties of the crystals were assessed by mechanical, structural, and crystallographic analyses. The results support the hypothesis that the cholesterol crystals can be considered, at least within the framework of the proposed mechanism, a possible cause of myocardial infarction.
Radical‐Triggered Three‐Component Coupling Reaction of Alkenylboronates, α‐Halocarbonyl Compounds, and Organolithium Reagents: The Inverse Ylid Mechanism
Authors: Tappin Nicholas D. C. , Gnägi‐Lux Manuel , Renaud Philippe
Published: June 2018

An operationally simple protocol to affect a radical addition to alkenylboronates that spontaneously undergo a [1,2]‐metalate shift is described. Overall, the reaction is a three‐component coupling of an organolithium, alkenylboronic ester, and halide which takes place with broad scope and good to excellent yields. Experimental mechanistic investigations support the formation of a boron inverse ylid intermediate.
Molekulare Eis‐Tänzer
Authors: Groß Michael
Published: June 2018

Fische in polaren Gewässern benutzen zum Frostschutz kleine Proteine oder Glykoproteine. Während die Funktionsweise der reinen Proteine bereits vor Jahren aus ihren Strukturen erschlossen werden konnte, sind die Glykoproteine strukturell flexibel und ihre Bindungsmechanismen bleiben umstritten. Eine Computersimulation legt nun nahe, dass sie auf dem Eis herumwandern können.
Design of a high power PIN‐diode controlled switchable RF transmit array for TRASE RF imaging
Authors: Der Eric , Volotovskyy Vyacheslav , Sun Hongwei , Tomanek Boguslaw , Sharp Jonathan C.
Published: June 2018

Some MRI applications require the generation of a series high power RF pulses in which the spatial transmit B1 field pattern over the sample is modified between one pulse and the next. This requirement may be realized by a RF transmit array with the capability to enable and disable individual elements to switch between field patterns with switching times of the order 10 μs. Our application is for a TRASE (“Transmit Array Spatial Encoding”) array for which short high power pulses are necessary to achieve high resolution (mm‐level) spatial encoding. We present designs for coil array, coil switching circuits, and a high power PIN diode driver together capable of robust and rapid switching of short (~120 μs) high power pulses for a 24 cm TRASE phase gradient coil suitable for imaging extremities at 8 MHz. We describe in detail the selection of suitable coil components and switch circuit designs to satisfy a specific requirement for maximum B1 field strength, and provide all circuit designs.
Design of Perchlorotriphenylmethyl (PTM) Radical‐Based Compounds for Optoelectronic Applications: The Role of Orbital Delocalization
Authors: Diez‐Cabanes Valentín , Seber Gonca , Franco Carlos , Bejarano Francesc , Crivillers Nuria , Mas‐Torrent Marta , Veciana Jaume , Rovira Concepció , Cornil Jérôme
Published: June 2018

Perchlorotriphenylmethyl (PTM) radical‐based compounds are widely exploited as molecular switching units. However, their application in optoelectronics is limited by the fact that they exhibit intense absorption bands only in a narrow range of the UV region around 385 nm. Recent experimental works have reported new PTM based compounds which present a broad absorption in the visible region although the origin of this behavior is not fully explained. In this context, Time‐Dependent Density Functional Theory (TD‐DFT) calculations have been performed to rationalize the optical properties of these compounds. Moreover, a new compound based on PTM disubstituted with bistriazene units has been synthetized and characterized to complete the set of available experimental data on related compounds. The results point to the delocalization of the Highest Occupied Molecular Orbital (HOMO) of the substituents along the PTM core as the origin of the new high absorption bands in the visible region. As a consequence, the absorption of the PTM‐based compounds can be tuned via the choice of the nature of the donor substituent, type of connection, and number of substituents.
Overview of Genetically Engineered Mouse Models of Prostate Cancer and Their Applications in Drug Discovery
Authors: Civenni Gianluca , Carbone Giuseppina M. , Catapano Carlo V.
Published: June 2018

Prostate cancer (PCa) is the most common malignant visceral neoplasm in males in Western countries. Despite progress made in the early treatment of localized malignancies, there remains a need for therapies effective against advanced forms of the disease. Genetically engineered mouse (GEM) models are valuable tools for addressing this issue, particularly in defining the cellular and molecular mechanisms responsible for tumor initiation and progression. While cell and tissue culture systems are important models for this purpose as well, they cannot recapitulate the complex interactions within heterotypic cells and the tumor microenvironment that are crucial in the initiation and progression of prostate tumors. Limitations of GEM models include resistance to developing invasive and metastatic tumors that resemble the advanced stages of human PCa. Nonetheless, because genetic models provide valuable information on the human condition that would otherwise be impossible to obtain, they are increasingly employed to identify molecular targets and to examine the efficacy of cancer therapeutics. The aim of this overview is to provide a brief but comprehensive summary of GEM models for PCa, with particular emphasis on the strengths and weaknesses of this experimental approach. © 2018 by John Wiley & Sons, Inc.
Relationship between Birefringence and Surface Morphology in Single‐Crystal Diamonds Grown by MPCVD
Authors: Zhao Yun , Guo Yanzhao , Lin Liangzhen , Zheng Yuting , Hei Lifu , Liu Jinlong , Wei Junjun , Chen Liangxian , Li Chengming
Published: June 2018

Single‐crystal diamonds are successfully synthesized using microwave plasma chemical vapor deposition. A smooth and flat single‐crystal surface is obtained by optimizing the size relationship between the seed substrate and the square hole of the shielding ring. When the sample grows higher than the polycrystalline diamond on the molybdenum holder, the surface becomes uneven. The polarization characteristics of two kinds of chemical vapor deposition (CVD) layers are compared between flat and uneven surfaces. Abnormal high‐order birefringence occurs in both morphologies, which is related to the dislocation density in the CVD layers. The higher the dislocation density of the sample, the more obvious the high‐order anomalous birefringence. High‐pressure high‐temperature seed substrates have obvious defects, such as dislocations, stacking faults, and boundaries of the growth sector, and these defects are mostly distributed at the edge of seed substrates. When the diamond surface demonstrates an edge‐to‐center morphology, the dislocations in the seed substrate, interface‐induced dislocations, and dislocations formed in the growth layer begin to converge toward the central region of the CVD layer, which results in a smaller area of low stress in the center of the CVD layer. High dislocation density causes the crystal to have a mosaic structure and orientation deviation.
Optimal design of third‐order microstrip bandpass filters by direct synthesis technique (DST)
Authors: Xiao Fei , Gong Huarong , Zhang Yong
Published: June 2018

To design microstrip filters is not easy for the sake of their distributed‐element effect. Undoubtedly, to understand their physical mechanism is very important to their design. In this paper, one effective approach to design some third‐order microstrip bandpass filters with each of 2 transmission zeros at each side of the passband is discussed. Lumped‐element equivalent circuits are used to represent these microstrip filters. Then, these lumped‐element equivalent circuits can be synthesized by direct synthesis technique we recently proposed, so that it is likely to calculate initial structural parameters of these microstrip filters and then facilitate their design. Verified by the measured results of the filter designed through the approach in this paper, the performance of the filters is close to ideal frequency responses. Furthermore, another third‐order microstrip bandpass filter is presented, in which open‐circuited stubs at input/output ports are introduced to suppress one specified harmonic to improve out‐of‐band attenuation.
Nutrient supply rates in a boreal extreme‐rich fen using ion exchange membranes
Authors: Hartsock Jeremy A. , Bremer Eric
Published: June 2018

Plant Root Simulator (PRS®) probes have been widely used to assess soil nutrients in the Athabasca Oil Sands Region of northern Alberta, Canada, but their optimum method of use and functionality in natural boreal fens and reclaimed wetlands needs to be determined. A PRS probe consists of an anion or cation exchange resin membrane that is housed in a plastic support. We assessed nutrient adsorption by PRS probes over three incubation periods (2, 24, and 384 hr) in a boreal extreme‐rich fen, a system with moderately high pore water electrical conductivity and a peatland site type that has been targeted in oil sand wetland reclamation. Ion adsorption by PRS probes was similar at 24 and 384 hr for ammonium, nitrate, phosphate, calcium, and magnesium, indicating that a stable or dynamic equilibrium was reached. However, potassium declined from 24 to 384 hr, likely due to displacement by more strongly held cations, while iron and manganese increased, likely due to increasingly anaerobic conditions. The finding that most nutrients were close to equilibrium on PRS probes within 24 hr has important implications for implementation and interpretation of PRS probe data in wetlands with moderately high pore water electrical conductivity.
Correlation with invasive left ventricular filling pressures and prognostic relevance of the echocardiographic diastolic parameters used in the 2016 ESC heart failure guidelines and in the 2016 ASE/EACVI recommendations: a systematic review in patients with heart failure with preserved ejection fraction
Authors: Nauta Jan F. , Hummel Yoran M. , van der Meer Peter , Lam Carolyn S.P. , Voors Adriaan A. , van Melle Joost P.
Published: June 2018

Aims

Five echocardiographic parameters—left atrial volume index, left ventricular mass index, tricuspid regurgitation velocity, myocardial tissue velocity, and the ratio of early mitral inflow to tissue velocity of the mitral annulus (E/e')—are recommended in both the current European Society of Cardiology heart failure guidelines and the American Society of Echocardiography/European Association of Cardiovascular Imaging recommendations for the evaluation of left ventricular diastolic function. We aimed to perform a systematic review of these echocardiographic parameters at resting conditions for their correlation with left ventricular filling pressures in patients with heart failure with preserved ejection fraction (HFpEF). In addition, the prognostic value of these parameters was assessed.

Methods and results

Nine studies reported the correlation between echocardiography and invasive haemodynamics, and 18 papers reported on the prognostic value of echocardiography in HFpEF. Among the parameters, most data were reported for E/e'. The pooled correlation coefficient r was 0.56 for the relation between E/e' and invasively measured filling pressures. Combined weighted‐mean meta‐analysis of prognostic studies resulted in a hazard ratio of 1.05 (95% confidence interval 1.03–1.06) per unit increase in E/e' for the combined outcome of all‐cause mortality and cardiovascular hospitalization. The other echocardiographic parameters, when taken individually, had similar or lower association with prognosis.

Conclusion

Only a small number of studies validated the use of echocardiographic parameters at rest in patients with HFpEF. The best established parameter appears to be E/e', but the existing data only show modest correlations of E/e' with invasive filling pressures and outcomes in HFpEF.
Synthesis of Amides from Alcohols and Amines Through a Domino Oxidative Amidation and Telescoped Transamidation Process
Authors: Drageset Audun , Bjørsvik Hans‐René
Published: June 2018

The amide bond formation is of paramount importance in organic synthesis, both within academic research and industrial development and manufacturing of pharmaceutical chemicals and other biologically active compounds. Despite this fact, as well as the ever‐increasing treatment costs of side streams and other environmental concerns regarding handling and transportation of hazardous reagents, contemporary synthesis has elicited few new reactions and methods for the preparation of amides. Herein, we reveal a high yielding and expedite two‐step telescoped synthetic process that comprises a domino oxidative amidation and transamidation for the creation of amides. The process utilizes alcohols and amines as reaction pairs with TEMPO and Fe ions as catalytic system and 1,3‐dichloro‐5,5‐dimethyl hydantoin as a terminal oxidant. The oxidative amidation and transamidation process is conducted under benign reaction conditions and short reaction time (≈ 30 min.) in a two‐step telescoped fashion by means of a multi‐jet oscillating disk (MJOD) continuous‐flow reactor platform. The disclosed process integrates alcohol oxidation and amide formation to afford target amide in yields up to 90 %. The method operates with both primary and secondary amines together, but was hampered when bulky amines and/or alcohols were used as reagent/substrate.
Synthesis of 1,2,3,4,5‐Penta(methoxycarbonyl)cyclopentadienides through Electrocyclic Ring Closure and Ring Contraction Reactions
Authors: Salikov Rinat F. , Trainov Konstantin P. , Platonov Dmitry N. , Belyy Alexander Yu. , Tomilov Yury V.
Published: June 2018

The mechanism for the reaction of dimethyl malonate with dimethyl acetylenedicarboxylate in the presence of pyridine and acetic acid to form isomeric octa(methoxycarbonyl)cycloheptadienes was established. The formation of intermediary N‐[di(methoxycarbonyl)vinyl]pyridinium acetate was proven by means of NMR spectroscopy. On the basis of the established mechanism, dimethyl dibromosuccinate was proposed to be used instead of dimethyl acetylenedicarboxylate. A novel method for the synthesis of penta(methoxycarbonyl)cyclopentadienylsodium through the reduction of hepta(methoxycarbonyl)cycloheptatriene with sodium borohydride, electrocyclic ring contraction and retro‐[2+2]‐cycloaddition was developed.
Graphene Doped Mn2O3 Nanofibers as a Facile Electroanalytical DNA Point Mutation Detection Platform for Early Diagnosis of Breast/Ovarian Cancer
Authors: Tripathy Suryasnata , Gangwar Rahul , Supraja Patta , Rao AVSS Narayana , Vanjari Siva Rama Krishna , Singh Shiv Govind
Published: June 2018

This paper demonstrates a simple, label‐free detection methodology for detecting single point DNA mutations. Single point mutation detection is a key enabler for diagnosis and prevention of several genetic disorders that manifest into cancers. Specifically for this purpose, herein, an electrochemical biosensor utilizing electrospun graphene doped manganese III oxide nanofibers (GMnO) is developed. The charge transfer resistance offered by GMnO is extremely sensitive to the localized change in the conductivity. This sensitivity, attributed to the low band gap of Mn2O3 and high charge transfer kinetics of graphene, is explored in the proposed mutation detection platform. As a proof of concept, ultrasensitive detection of BRCA1 gene specific point mutation is demonstrated. The target specific single stranded probe DNA is immobilized onto GMnO modified glassy carbon working electrodes via chemisorption. Post target‐DNA hybridization, differential pulse voltammetry is employed to facilitate detection of targeted point mutation, wherein, difference in peak currents is used to distinguish the target DNA as normal or mutant. Efficiency of the proposed method is evaluated against a target concentration ranging from 10 pM−1 μM. With respect to the mutated target DNA, the LoD of the proposed device is found to be 0.8±0.069 pM. The proposed approach can be extended for detecting any mutation/hybridization of interest by simply adapting an appropriate functionalization protocol.
SDN/NFV‐enabled performance estimation framework for SFC optimization
Authors: Yi Bo , Wang Xingwei , Huang Min
Published: June 2018

Many network function virtualization management and orchestration frameworks have been proposed to offer an agile and automated service deployment with a set of virtual network function (VNF) placement and chaining algorithms. However, once the services are deployed, less attention is paid to the subsequent supervision on their performance which may be affected by the dynamic changing network conditions. In order to guarantee the performance of services, this article designs and presents a service function chain performance estimation framework, which can be used to complement the network function virtualization orchestrators by providing performance estimation and optimization for the already deployed services. In particular, the performance estimation is implemented based on the min‐plus algebra theory, and the optimization is fulfilled by using two VNF migration approaches on the basis of greedy and load balance, respectively. The proposed framework can (1) evaluate and compare existing VNF placement algorithms by statistics on service performance estimation, (2) estimate and optimize the performance of services by using VNF migration approaches, (3) integrate the VNF placement algorithms and VNF migration approaches, thus producing more efficient future solutions. Finally, this article presents an implementation of the proposed framework and evaluates its effectiveness in an experimental environment.
B‐Lynch plus technique for uterine conservative surgery in an asymmetric atonic uterus
Authors: Kaveh Mania , Tahermanesh Kobra , Hanjani Soheil , Abed Seyedeh Mehr
Published: June 2018

A useful addition to a standard B‐Lynch technique for management of asymmetric atonic uterus.
Correlation of intracellular oxygen and cell metabolism by simultaneous PLIM of phosphorescent TLD1433 and FLIM of NAD(P)H
Authors: Kalinina Sviatlana , Breymayer Jasmin , Reeß Kirsten , Lilge Lothar , Mandel Arkady , Rück Angelika
Published: June 2018

During photodynamic therapy (PDT), disruption of cell respiration and metabolic changes could be one of the first events. Photophysical characteristics of the photosensitizer (PS) and its specific redox potential define consumption of molecular oxygen followed by generation of reactive oxygen species. The potential PS TLD1433 is based on transition metal Ru(II) and possess an oxygen‐dependent luminescence. This enables the study of oxygen consumption by PS‐phosphorescence lifetime imaging (PLIM) and simultaneously changes the cellular metabolic state by nicotinamide adenine dinucleotide (NAD(P)H)‐fluorescence lifetime imaging (FLIM). Within this study, localization and cellular function of TLD1433 is investigated in bladder carcinoma cells using time‐resolved and confocal laser scanning microscopy. Simultaneous FLIM/PLIM of NAD(P)H and TLD1433 during PDT correlated oxygen consumption, redox state and cellular energy metabolism. Our investigations aimed to provide a personalized protocol in theranostic PDT procedures and demonstrate the potential use of TLD1433 PDT also under hypoxic conditions, which are otherwise difficult to treat.