bluuebunny/crossref_metadata_2025 huggingface dataset:
Kontrolle der Molmassenverteilung durch Polymerisation in der analytischen Ultrazentrifuge
Authors: Spinnrock Andreas , Cölfen Helmut
Published: February 2018

Molmassenverteilungen sind in der makromolekularen Chemie von großem Interesse. Ein Ansatz, um breite Molmassenverteilungen zu erhalten und ihre Form zu kontrollieren, ist es, die Initiatorkonzentration in freien radikalischen Polymerisationen einzustellen. Ein kontrolliert einstellbarer Gradient der Initiatorkonzentration führt potenziell zu maßgeschneiderten Molmassenverteilungen. Analytische Ultrazentrifugation (AUZ) wurde genutzt, um den Konzentrationsgradienten eines Makroinitiators einzustellen und zu detektieren. Über anschließende Photopolymerisation eines gleichmäßig verteilten Monomers werden die gewünschten Kettenlängenverteilungen erhalten. Die entstehenden Verteilungen werden durch einen Schulz‐Flory‐Ansatz beschrieben und berechnet. Die gewünschten Konzentrationsprofile werden im Voraus simuliert und können jederzeit durch die optischen Systeme der Zentrifuge detektiert werden. Durch Vorhersagen aus Simulationen, die mit der belastbaren Theorie der AUZ erstellt werden, können daher jetzt maßgeschneiderte Molmassenverteilungen hergestellt werden.
Benzylic Fluorination of Aza‐Heterocycles Induced by Single‐Electron Transfer to Selectfluor
Authors: Danahy Kelley E. , Cooper Julian C. , Van Humbeck Jeffrey F.
Published: February 2018

A selective and mild method for the benzylic fluorination of aromatic azaheterocycles with Selectfluor is described. These reactions take place by a previously unreported mechanism, in which electron transfer from the heterocyclic substrate to the electrophilic fluorinating agent Selectfluor eventually yields a benzylic radical, thus leading to the desired C−F bond formation. This mechanism enables high intra‐ and intermolecular selectivity for aza‐heterocycles over other benzylic components with similar C−H bond‐dissociation energies.
Atomic Force Microscopy for Molecular Structure Elucidation
Authors: Gross Leo , Schuler Bruno , Pavliček Niko , Fatayer Shadi , Majzik Zsolt , Moll Nikolaj , Peña Diego , Meyer Gerhard
Published: February 2018

Using scanning probe microscopy techniques, at low temperatures and in ultrahigh vacuum, individual molecules adsorbed on surfaces can be probed with ultrahigh resolution to determine their structure and details of their conformation, configuration, charge states, aromaticity, and the contributions of resonance structures. Functionalizing the tip of an atomic force microscope with a CO molecule enabled atomic‐resolution imaging of single molecules, and measurement of their adsorption geometry and bond‐order relations. In addition, by using scanning tunneling microscopy and Kelvin probe force microscopy, the density of the molecular frontier orbitals and the electric charge distribution within molecules can be mapped. Combining these techniques yields a high‐resolution tool for the identification and characterization of individual molecules. The single‐molecule sensitivity and the possibility of atom manipulation to induce chemical reactions with the tip of the microscope open up unique applications in chemistry, and differentiate scanning probe microscopy from conventional methods for molecular structure elucidation. Besides being an aid for challenging cases in natural product identification, atomic force microscopy has been shown to be a powerful tool for the investigation of on‐surface reactions and the characterization of radicals and molecular mixtures. Herein we review the progress that high‐resolution scanning probe microscopy with functionalized tips has made for molecular structure identification and characterization, and discuss the challenges it will face in the years to come.
Preparation and coagulation performance of hybrid coagulant polyacrylamide–polymeric aluminum ferric chloride
Authors: Wang Xinlei , Jiang Shaojie , Tan Siying , Wang Xun , Wang Hongwu
Published: February 2018

In this study, we synthesized a novel hybrid coagulant, polyacrylamide (PAM)–polymeric aluminum ferric chloride (PAFC), by the polymerization of acrylamide monomer with the redox system (NH4)2S2O8–NaHSO3. The factors affecting the PAM–PAFC hybrid coagulant were investigated in an orthogonal experiment. The maximum intrinsic viscosity was observed at an initiator mass fraction of 0.5%, a polymerization temperature of 50 °C, a monomer mass fraction of 20%, and a polymerization time of 4 h, which were the optimum synthesis parameters. The spatial network structure of the PAM–PAFC hybrid coagulant was graphically determined by scanning electron microscopy. Hybrid PAM–PAFC was adopted to treat the kaolin–humic acid suspension and the synthetic dye wastewater. The effect of the coagulant dosage and pH on the coagulant experiments were examined. The coagulant experiment on the kaolin–humic acid suspension showed that the optimum treatment efficiency was achieved at a coagulants dosage of 0.6 mg/L, at which level the turbidity reductions with the inorganic PAFC coagulant, PAM–PAFC composite, and PAM–PAFC hybrid were 95.30%, 95.84%, and 98.38%, respectively. Treatment with the PAM–PAFC hybrid coagulant was also effective in removing Congo Red and Direct Fast Turquoise Blue GL; the color‐removal efficiencies for these dyes were higher than 93% and 94%, respectively. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46355.
Gambusia holbrooki, the ‘tadpolefish’: The impact of its predatory behaviour on four protected species of European amphibians
Authors: Vannini Andrea , Bruni Giacomo , Ricciardi Giulia , Platania Leonardo , Mori Emiliano , Tricarico Elena
Published: February 2018

Biological invasions are widely regarded as the second major cause of the current global biodiversity crisis. Freshwater environments in particular include many habitats and species of conservation concern. Among those, amphibians are threatened worldwide by habitat loss and by the introduction of alien taxa, including pathogens and fish.

The North American mosquitofish Gambusia spp. have been introduced throughout the world for the biological control of mosquitoes, and have established alien populations in over 110 countries. Their impact on native freshwater vertebrates, especially in Europe, is still poorly known.

Here, the predatory impact of mosquitofish on the larval stages of four European amphibian species (Hyla intermedia, Triturus carnifex, Pelophylax kl. hispanicus, and Bufotes balearicus), locally abundant in Central Italy, has been investigated under laboratory conditions to assess whether any difference occurs in species vulnerability and interactions with the predator, as their breeding sites are often invaded by mosquitofish. Larval mortality and fish attacks, as well as observations on fish predatory behaviour, were recorded at four time intervals (10 min, 1 h, 6 h, and 24 h) and at three different prey abundances (with five, 10, and 20 larvae).

A significant difference in predation rate for species, exposure time, and larval abundance occurred, with H. intermedia being the most vulnerable species and B. balearicus being the least vulnerable species. An increase in exposure time increased the rate of predation, whereas small groups of larvae (i.e. <10 individuals) appeared to be far more vulnerable to fish attack compared with the larger groups.

Mosquitofish show considerable potential to prey upon the larvae of European amphibians, representing a serious threat for their conservation. Appropriate management and legislative strategies are thus necessary to prevent the further introduction and spread of this alien fish in natural environments.
Geophysical surveying of the ancient walls of the town of Cagliari, Italy, by means of refraction and up‐hole seismic tomography techniques
Authors: Balia Roberto , Pirinu Andrea
Published: February 2018

The ancient walls of Santa Croce in the town of Cagliari (Sardinia, Italy), date back to the Middle Age and have had, until the nineteenth century, several interventions with superpositions and modifications. Beyond the historical and archaeological interest, the study of the structure of the ancient walls became necessary in view of building an underground car parking just at the base of the walls itself. With this purpose, in addition to classical archaeological surveys a geophysical non‐destructive survey with seismic techniques has been carried out, namely two refraction tomographies aimed at characterizing the rocks at the base of the walls, and four up‐hole tomographies across the walls itself. These geophysical surveys provide good geotechnical information on the foundation condition, the problematic feasibility of the underground parking and, along with the archaeological procedures, on the heterogeneous structure of the walls.
Construction of a Triangle‐Shaped Trimer and a Tetrahedron Using an α‐Helix‐Inserted Circular Permutant of Cytochrome c555
Authors: Oda Akiya , Nagao Satoshi , Yamanaka Masaru , Ueda Ikki , Watanabe Hiroki , Uchihashi Takayuki , Shibata Naoki , Higuchi Yoshiki , Hirota Shun
Published: February 2018

Highly‐ordered protein structures have gained interest for future uses for biomaterials. Herein, we constructed a building block protein (BBP) by the circular permutation of the hyperthermostable Aquifex aeolicus cytochrome (cyt) c555, and assembled BBP into a triangle‐shaped trimer and a tetrahedron. The angle of the intermolecular interactions of BBP was controlled by cleaving the domain‐swapping hinge loop of cyt c555 and connecting the original N‐ and C‐terminal α‐helices with an α‐helical linker. We obtained BBP oligomers up to ≈40 mers, with a relatively large amount of trimers. According to the X‐ray crystallographic analysis of the BBP trimer, the N‐terminal region of one BBP molecule interacted intermolecularly with the C‐terminal region of another BBP molecule, resulting in a triangle‐shaped structure with an edge length of 68 Å. Additionally, four trimers assembled into a unique tetrahedron in the crystal. These results demonstrate that the circular permutation connecting the original N‐ and C‐terminal α‐helices with an α‐helical linker may be useful for constructing organized protein structures.
Frequency‐Independent and Colossal Dielectric Permittivity of Platy Alumina/Few‐Layer Graphene Multilayered Composites
Authors: Choi Ki‐Beom , Lee Sung‐Min , Hwang Jae‐yeol , Yoon Dae Ho , Lee Kyu Hyoung , Kim Jong‐Young
Published: February 2018

In this work, we investigated the dielectric property of layer‐structured Al2O3/few‐layer graphene (FLG) composite by high temperature impedance spectroscopic analysis. The sintered composites have highly enhanced permittivity (ε = 17.3) compared to pure platy alumina (ε = 7.3) with low dielectric loss (tanδ ~ 10−3). Percolative permittivity of the composites exhibits almost frequency‐independent behavior at 1 Hz to 1 MHz even though the real permittivity was increased, compared to that of pure platy alumina. Such behavior can be explained by intervening dielectric interface between alumina and FLG based on multilayer filler model. After percolation threshold (FLG > 0.75 vol %), the permittivity is further enhanced up to ~260 (@1 kHz), which amounts to >35 fold increase, compared to pure platy alumina because of interfacial capacitance between FLG platelets and alumina. According to temperature‐dependent impedance analysis, a dielectric relaxation due to Al2O3/FLG interface is observed in the frequency range of 1 Hz to 1 kHz at high temperature (RT = 400°C) besides that due to Al2O3 grains (>10 MHz). Real permittivity increases up to >20 000 at 400°C at low frequency, whereas dielectric loss remains as tanδ ~ 3 × 10−4. High temperature impedance analysis shows that the effect of interface between Al2O3 and FLG is responsible for such dielectric relaxation at high temperature.
Lipophilicity evaluation of some thiazolyl‐1,3,4‐oxadiazole derivatives with antifungal activity
Authors: Stoica Cristina Ioana , Ionuț Ioana , Vlase Laurian , Tiperciuc Brîndușa , Marc Gabriel , Oniga Smaranda , Araniciu Cătălin , Oniga Ovidiu
Published: February 2018

The chromatographic behavior of a series of thiazolyl‐1,3,4‐oxadiazoles with antifungal activity was studied by reverse‐phase thin‐layer chromatography (RP‐TLC). The lipophilicity parameters derived from RP‐TLC were correlated with the data derived from liquid‐chromatography mass‐spectrometry. Good linear relationships were observed between the chromatographic lipophilicity parameters and the theoretical lipophilicity descriptors (logP) generated by various computer software and internet modules. Principal component analysis, applied on the experimental chromatographic lipophilicity indices and the theoretically calculated logP, enabled us to obtain a lipophilicity chart for better vizualization of the similarities and differences of the investigated compounds, which were grouped by k‐means clustering in two congeneric classes.
Motivations of sustainable entrepreneurship and their impact of enterprise performance in Gauteng Province, South Africa
Authors: Nhemachena Charles , Murimbika McEdward
Published: February 2018

The paper discussed motivations of sustainable entrepreneurship in Gauteng Province, South Africa, and estimated relationships between these motivations and enterprise performance. Despite the growing field of sustainable entrepreneurship, most of the available literature has been mainly theoretical and qualitative or has focused on developed countries. This paper contributes to addressing this gap through empirical analysis based on primary survey data from 91 sustainable entrepreneurs. Reliability of the performance and motivation scales were subjected to the Cronbach's alpha coefficient test, and the results were acceptable. The exploratory factor analysis indicated that the motivations of sustainable entrepreneurship factored into 4 dimensions: extrinsic, intrinsic, income security and financial independence, and necessity motivations. Regression analysis revealed that extrinsic and intrinsic motivations are important determinants of enterprise performance. These motivations can be targeted to promote sustainable entrepreneurship in addition to complementary support such as improving business management skills and competencies of sustainable entrepreneurs.
A simulation tool to promote active learning of controlled rectifiers
Authors: Chibante Rui , Vaz De Carvalho Carlos , Ferreira Paulo
Published: February 2018

The use of interactive simulation tools can effectively support the adoption of active learning methodologies in Engineering Education therefore increasing the motivation of the students and improving their knowledge acquisition. This paper presents the design and development of a pedagogical simulation tool for the teaching and self‐studying of thyristor controlled rectifiers. The application enables the user to vary the thyristors firing angle and to analyze its influence on the rectifier output voltage. Waveforms are plotted using specific heuristics instead of solving the system of equations that governs the circuit's operation which makes the application extremely fast. The software is also independent of the operating system and does not require any kind of installation. In comparison with other existing tools, the proposed system provides a much simpler approach, user‐friendlier, and with an easier learning curve. Evaluation results showed that students reported a positive feedback from the use of the simulation tool.
A Cytidine Phosphoramidite with Protected Nitroxide Spin Label: Synthesis of a Full‐Length TAR RNA and Investigation by In‐Line Probing and EPR Spectroscopy
Authors: Weinrich Timo , Jaumann Eva A. , Scheffer Ute , Prisner Thomas F. , Göbel Michael W.
Published: February 2018

EPR studies on RNA are complicated by three major obstacles related to the chemical nature of nitroxide spin labels: Decomposition while oligonucleotides are chemically synthesized, further decay during enzymatic strand ligation, and undetected changes in conformational equilibria due to the steric demand of the label. Herein possible solutions for all three problems are presented: A 2‐nitrobenzyloxymethyl protective group for nitroxides that is stable under all conditions of chemical RNA synthesis and can be removed photochemically. By careful selection of ligation sites and splint oligonucleotides, high yields were achieved in the assembly of a full‐length HIV‐1 TAR RNA labeled with two protected nitroxide groups. PELDOR measurements on spin‐labeled TAR in the absence and presence of arginine amide indicated arrest of interhelical motions on ligand binding. Finally, even minor changes in conformation due to the presence of spin labels are detected with high sensitivity by in‐line probing.
The Gold(I)‐Mediated Domino Reaction to Fused Diphenyl Phosphoniumfluorenes: Mechanistic Consequences for Gold‐Catalyzed Hydroarylations and Application in Solar Cells
Authors: Arndt Sebastian , Borstelmann Jan , Eshagh Saatlo Rebeka , Antoni Patrick W. , Rominger Frank , Rudolph Matthias , An Qingzhi , Vaynzof Yana , Hashmi A. Stephen K.
Published: February 2018

A domino sequence, involving a phosphinoauration and a gold‐catalyzed 6‐endo‐dig cyclization step, was developed. Starting from modular and simple‐to‐prepare phosphadiynes, π‐extended phosphoniumfluorenes were synthesized. The mechanistic proposal was supported by kinetic measurements and by the trapping of key intermediates. These led to important conclusions for the gold‐catalyzed hydroarylation mechanism. Cyclic voltammetry (CV) and UV/Vis spectroscopy measurements indicated interesting properties for materials science. The phosphoniumfluorene structure was tested as a hole‐blocking layer in perovskite solar cells of inverted architecture. Devices with the phosphoniumfluorene exhibited an efficiency of 14.2 %, which was much higher than that of devices without (10.7 %).
Production of Multilayer Graphene in a Vibratory Disk Mill
Authors: Trüe Michael , Aman Sergej , Müller Peter , Hintz Werner , Hirsch Sören
Published: February 2018

Optimale Prozessbedingungen für das mikromechanische Abblättern von mehrschichtigem Graphen werden mit einer Scheibenschwingmühle realisiert, in der eine hochviskose Flüssigkeit bestehend aus Zucker und Graphitpartikeln zerkleinert wird. Die Bedingungen, bei denen die Scherkräfte im Prozess in der Scheibenschwingmühle entstehen, werden untersucht. Graphenblätter mit Schichtdicken von 2 – 10 Schichten werden gewonnen. Das erhaltene mehrschichtige Graphen kann bei der Herstellung von Lithium‐Ionen‐Akkumulatoren eingesetzt werden.
Scripting as an Approach to Automated CFD Simulation for Packed Bed Catalytic Reactor Modeling
Authors: Fernengel Johanna , Habla Florian , Hinrichsen Olaf
Published: February 2018

In recent years computational fluid dynamics (CFD) has become a widely applied tool for the simulation of catalytic fixed‐bed reactors and numerous authors have contributed towards methods for random packed bed generation and flow simulation. The presented approach focuses on an automated simulation routine realized through bash and python scripting covering multiple entire simulation runs including preprocessing, simulation as well as post‐processing based on open‐source software. As an example, the routine is demonstrated with a case study on catalytic fixed‐bed reactors.
Discovery of Molidustat (BAY 85‐3934): A Small‐Molecule Oral HIF‐Prolyl Hydroxylase (HIF‐PH) Inhibitor for the Treatment of Renal Anemia
Authors: Beck Hartmut , Jeske Mario , Thede Kai , Stoll Friederike , Flamme Ingo , Akbaba Metin , Ergüden Jens‐Kerim , Karig Gunter , Keldenich Jörg , Oehme Felix , Militzer Hans‐Christian , Hartung Ingo V. , Thuss Uwe
Published: February 2018

Small‐molecule inhibitors of hypoxia‐inducible factor prolyl hydroxylases (HIF‐PHs) are currently under clinical development as novel treatment options for chronic kidney disease (CKD) associated anemia. Inhibition of HIF‐PH mimics hypoxia and leads to increased erythropoietin (EPO) expression and subsequently increased erythropoiesis. Herein we describe the discovery, synthesis, structure–activity relationship (SAR), and proposed binding mode of novel 2,4‐diheteroaryl‐1,2‐dihydro‐3H‐pyrazol‐3‐ones as orally bioavailable HIF‐PH inhibitors for the treatment of anemia. High‐throughput screening of our corporate compound library identified BAY‐908 as a promising hit. The lead optimization program then resulted in the identification of molidustat (BAY 85‐3934), a novel small‐molecule oral HIF‐PH inhibitor. Molidustat is currently being investigated in clinical phase III trials as molidustat sodium for the treatment of anemia in patients with CKD.
Prevention of liver cancer with new curative hepatitis C antivirals: Real‐world challenges
Authors: Soriano Vicente , Tefferi Ayalew
Published: February 2018

New antiviral therapies cure most patients with hepatitis C and prevent the development of cirrhosis and hepatocellular carcinoma. The major challenges for global hepatitis C virus eradication are the identification of patients with chronic hepatitis C, referrals to treatment, and elevated drug prices. See also pages 1644‐46.
Hepatitis C: When high drug prices preclude patient benefit
Authors: Kantarjian Hagop M. , Paul Shilpa
Published: February 2018

Currently, there are at least 6 drug companies that have developed curative treatments for hepatitis C. Drugs that cure hepatitis C can save up to one‐half million individuals every year, but these therapies are neither accessible nor affordable. See also pages 1647‐49.
Precision in the reproduction of colored coatings
Authors: Meichsner Georg , Hiesgen Renate , Etzl Thomas , Vanderhoeven Marcel , Brinz Thomas
Published: February 2018

The objective of this study was to apply Hotelling's T2‐statistics to color measurement data of colored coatings. It is described, how outliers can be detected by comparing T2 with an appropriate statistical distribution function. As an example, the precision in the reproduction of colored coatings produced in laboratory and prepared by a robot for high‐throughput experimentation was investigated on a turquoise coating. After elimination of outliers the precision of reproduction of the coatings color was determined by the sample color differences to the average color coordinates in CIELAB and DIN99 color spaces as well as with CIEDE2000 color differences. As expected, laboratory experimentation (reproducibility conditions) showed a lower precision of color reproduction as samples prepared with the high‐throughput experimentation device (repeatability conditions).
On the design of secure user authenticated key management scheme for multigateway‐based wireless sensor networks using ECC
Authors: Sutrala Anil Kumar , Das Ashok Kumar , Kumar Neeraj , Reddy Alavalapati Goutham , Vasilakos Athanasios V. , Rodrigues Joel J. P. C.
Published: February 2018

In wireless sensor networks (WSNs), there are many critical applications (for example, healthcare, vehicle tracking, and battlefield), where the online streaming data generated from different sensor nodes need to be analyzed with respect to quick control decisions. However, as the data generated by these sensor nodes usually flow through open channel, so there are higher chances of various types of attacks either on the nodes or on to the data captured by these nodes. In this paper, we aim to design a new elliptic curve cryptography–based user authenticated key agreement protocol in a hierarchical WSN so that a legal user can only access the streaming data from generated from different sensor nodes. The proposed scheme is based upon 3‐factor authentication, as it applies smart card, password, and personal biometrics of a user (for ticket generation). The proposed scheme maintains low computation cost for resource‐constrained sensor nodes, as it uses efficient 1‐way cryptographic hash function and bitwise exclusive‐OR operations for secure key establishment between different sensor nodes. The security analysis using the broadly accepted Burrows‐Abadi‐Needham logic, formal security verification using the popular simulation tool (automated validation of Internet security protocols and applications), and informal security show that the proposed scheme is resilient against several well‐known attacks needed for a user authentication scheme in WSNs. The comparison of security and functionality requirements, communication and computation costs of the proposed scheme, and other related existing user authentication schemes shows the superior performance of the proposed scheme.
Preparing for an uncertain future: migrating shorebird response to past climatic fluctuations in the Prairie Potholes
Authors: Steen Valerie , Skagen Susan K. , Noon Barry R.
Published: February 2018

The Prairie Pothole Region, situated in the northern Great Plains, provides important stopover habitat for migratory shorebirds. During spring migration in the U.S. Prairie Potholes, 7.3 million shorebirds refuel in the region's myriad small, freshwater wetlands. Shorebirds use mudflats, shorelines, and ephemeral wetlands that are far more abundant in wet years than dry years. Generally, climate change is expected to bring warmer temperatures, seasonality shifts, more extreme events, and changes to precipitation. The impacts to wetland habitats are uncertain. In the Prairie Potholes, earlier spring onset and warmer temperatures may advance drying of wetlands or, alternately, increased spring precipitation may produce abundant shallow‐water habitats. To look at the availability of habitats for migratory shorebirds under different climate regimes, we compared habitat selection between a historic wet year and a dry year using binomial random‐effects models to describe local and landscape patterns. We found that in the dry year shorebirds were distributed more northerly and among more permanent wetlands, whereas in the wet year shorebirds were distributed more southerly and among more temporary wetlands. However, landscape‐scale variation played a larger role in the dry year. At the local wetland scale, shorebirds selected similarly between years—for shallower wetlands and wetlands in croplands. Overall, while shorebirds were sensitive to local habitat conditions, they exhibited a degree of adaptive capacity to climate change impacts by their ability to shift on the landscape. This indicates an avenue through which management decisions can enhance climate change resilience for these species given an uncertain future—by preserving shallow‐water wetlands in croplands throughout the landscape.
Temperature and aridity regulate spatial variability of soil multifunctionality in drylands across the globe
Authors: Durán Jorge , Delgado‐Baquerizo Manuel , Dougill Andrew J. , Guuroh Reginald T. , Linstädter Anja , Thomas Andrew D. , Maestre Fernando T.
Published: February 2018

The relationship between the spatial variability of soil multifunctionality (i.e., the capacity of soils to conduct multiple functions; SVM) and major climatic drivers, such as temperature and aridity, has never been assessed globally in terrestrial ecosystems. We surveyed 236 dryland ecosystems from six continents to evaluate the relative importance of aridity and mean annual temperature, and of other abiotic (e.g., texture) and biotic (e.g., plant cover) variables as drivers of SVM, calculated as the averaged coefficient of variation for multiple soil variables linked to nutrient stocks and cycling. We found that increases in temperature and aridity were globally correlated to increases in SVM. Some of these climatic effects on SVM were direct, but others were indirectly driven through reductions in the number of vegetation patches and increases in soil sand content. The predictive capacity of our structural equation modelling was clearly higher for the spatial variability of N‐ than for C‐ and P‐related soil variables. In the case of N cycling, the effects of temperature and aridity were both direct and indirect via changes in soil properties. For C and P, the effect of climate was mainly indirect via changes in plant attributes. These results suggest that future changes in climate may decouple the spatial availability of these elements for plants and microbes in dryland soils. Our findings significantly advance our understanding of the patterns and mechanisms driving SVM in drylands across the globe, which is critical for predicting changes in ecosystem functioning in response to climate change.
Development of an Aluminium Doped TiO2 Nanoparticles‐modified Screen Printed Carbon Electrode for Electrochemical Sensing of Vanillin in Food Samples
Authors: Murtada Khaled , Jodeh Shehdeh , Zougagh Mohammed , Ríos Ángel
Published: February 2018

A new chemically modified electrode based on titanium dioxide nanoparticles (TiO2‐NPs) has been developed. Aluminium was incorporated into the TiO2‐NPs to prepare aluminium doped TiO2 nanoparticles (Al‐TiO2‐NPs). Aluminium doped TiO2 nanoparticles‐modified screen printed carbon electrode (Al‐TiO2‐NPs/SPCE) was employed as easy, efficient and rapid sensor for electrochemical detection of vanillin in various types of food samples. Al‐TiO2‐NPs were characterized by energy‐dispersive X‐ray (EDX), transmission electron microscopy (TEM), and X‐ray diffraction (XRD) and analyses showing that the average particle sizes varied for the Al‐NPs (7.63 nm) and Al‐TiO2‐NPs (7.47 nm) with spherical crystal. Cyclic voltammetry (CV) and linear sweep voltammetry (LSV) were used to optimize the analytical procedure. A detection limit of vanillin was 0.02 μM, and the relative standard deviation (RSD) was 3.50 %, obtained for a 5.0 μM concentration of vanillin. The electrochemical behaviour of several compounds, such as vanillic acid, vanillic alcohol, p‐hydroxybenzaldehyde and p‐hydroxybenzoic, etc., generally present in natural vanilla samples, were also studied to check the interferences with respect to vanillin voltammetric signal. The applicability was demonstrated by analysing food samples. The obtained results were compared with those provided by a previous method based on liquid chromatography for determination of vanillin.
Quantitative separation of hesperidin, chrysin, epicatechin, epigallocatechin gallate, and morin using ionic liquid as a buffer additive in capillary electrophoresis
Authors: Memon Almas F. , Solangi Amber R. , Memon Saima Q. , Mallah Arfana , Memon Najma
Published: February 2018

Recently, an increasing interest has been observed in ionic liquids (ILs) due to their potentialities in various chemical processes. ILs have some unique properties making them excellent additives in CE. In this work a simple, rapid, and reliable CZE method has been developed and validated using 1‐butyl‐3‐methyl imidazolium hexafluorophosphate (BMIM‐PF6) ionic liquid as a buffer additive for the determination/separation of five flavonoids including hesperedin, epicatechin (EC), epigallocatechin gallate (EGCG), and morin using photodiode array (PDA) detector. The effect of several parameters such as concentration and pH of the running buffer, applied voltage, and concentration of ionic liquid were optimized. CZE at 25°C with 25 mM borate buffer of pH 9.0 at an applied voltage of 17 kV by adding 17.5 mM of IL was found to be suitable for the separation/determination of all five analytes within 08 min. Validation of the method was performed in terms of linearity, accuracy, precision, and limit of detection and quantification. The calibration curves were plotted in the concentration range of 1–200 μg/mL for all five analytes. The response was linear with R2 = 0.990 for EC, chrysin, and hesperidin, 0.992 for morin, and 0.988 for EGCG. LOD and LOQ were obtained within the range of 0.4–0.5 and 1.4–1.7 μg/mL, respectively. The proposed method showed good reproducibility with RSD of less than 3% for both migration time and peak height. The method was successfully applied for the determination of flavonoids from citrus fruits and tea samples.
Simultaneous isolation and preconcentration of exosomes by ion concentration polarization
Authors: Marczak Steven , Richards Katherine , Ramshani Zeinab , Smith Elaine , Senapati Satyajyoti , Hill Reginald , Go David B. , Chang Hsueh‐Chia
Published: February 2018

Exosomes carry microRNA biomarkers, occur in higher abundance in cancerous patients than in healthy ones, and because they are present in most biofluids, including blood and urine, these can be obtained noninvasively. Standard laboratory techniques to isolate exosomes are expensive, time consuming, provide poor purity, and recover on the order of 25% of the available exosomes. We present a new microfluidic technique to simultaneously isolate exosomes and preconcentrate them by electrophoresis using a high transverse local electric field generated by ion‐depleting ion‐selective membrane. We use pressure‐driven flow to deliver an exosome sample to a microfluidic chip such that the transverse electric field forces them out of the cross flow and into an agarose gel which filters out unwanted cellular debris while the ion‐selective membrane concentrates the exosomes through an enrichment effect. We efficiently isolated exosomes from 1× PBS buffer, cell culture media, and blood serum. Using flow rates from 150 to 200 μL/h and field strengths of 100 V/cm, we consistently captured between 60 and 80% of exosomes from buffer, cell culture media, and blood serum as confirmed by both fluorescence spectroscopy and nanoparticle tracking analysis. Our microfluidic chip maintained this recovery rate for more than 20 min with a concentration factor of 15 for 10 min of isolation.
Design and engineering of sustainable process systems and supply chains by the P‐graph framework
Authors: Cabezas H. , Argoti A. , Friedler F. , Mizsey P. , Pimentel J.
Published: February 2018

The design of sustainable manufacturing processes and supply chains is rapidly becoming a critical issue. The reason is the necessity of providing for the needs of a growing human population which is increasingly prosperous across the globe. To this purpose, this review article explores the most important elements of sustainability science and couples them with the P‐graph framework, thereby rendering it possible to design feasible process and supply structures with great ease. Structure is an often‐overlooked aspect of process and supply chain design, in part because even relative simple processes or supply chains can have an enormous number of feasible structures. We further illustrate the application of these ideas with examples of energy generation processes and supply chains. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 624–636, 2018
Are individuals with loss‐of‐control eating more prone to dietary lapse in behavioural weight loss treatment? An ecological momentary assessment study
Authors: Manasse Stephanie M. , Schumacher Leah M. , Goldstein Stephanie P. , Martin Gerald J. , Crosby Ross D. , Juarascio Adrienne S. , Butryn Meghan L. , Forman Evan M.
Published: February 2018

Objective

Individuals with overweight/obesity and loss‐of‐control eating (LOC) may experience poorer outcomes from behavioural weight loss due to reactivity to internal (e.g., affective and physical) states that impact treatment adherence (e.g., dietary lapses). This study examined (a) whether the presence of LOC increased risk for dietary lapses and (b) the moderating role of LOC on the relation between internal states and dietary lapses.

Method

Individuals (n = 189) with overweight and obesity completed ecological momentary assessment early in behavioural weight loss.

Results

LOC was positively associated with dietary lapse. LOC did not moderate the relation between momentary changes in internal states and dietary lapses. However, the effect of average levels of internal states on lapses was attenuated for those with LOC.

Discussion

Results suggest that those with LOC are at higher risk of dietary lapse, whereas elevated average levels of internal states may contribute to early inadherence for those without LOC.
Long‐term Operation of High Temperature Polymer Electrolyte Membrane Fuel Cells with Fuel Composition Switching and Oxygen Enrichment
Authors: Pinar F. J. , Rastedt M. , Dyck A. , Wagner P.
Published: February 2018

The performance of commercially available High temperature polymer electrolyte membrane fuel cells (HT‐PEMFCs) cells was electrochemically (impedance spectroscopy, polarization curves, performance over time) and optically characterized ante and post mortem via micro‐computed tomography. Investigations on the performance gain, due to oxygen enrichment of cathode air and the capabilities of the commercial MEAs to switch and operate between pure hydrogen and synthetic dry reformate (78% H2 and 22% CO2), were carried out. Two experiments at constant load conditions were performed, Cycle 1 consisted of 12 h pure hydrogen operation followed by 12 h of synthetic reformate, while Cycle 2 was operated with 1 h of H2 followed by 5 h of synthetic reformate. The results revealed that oxygen enrichment improves mass transport from the gas flow channels to the cathode catalyst layer as well as catalyst utilization. Thus, oxygen concentration increase from 21% (air) to 30% at 0.3 A cm−2 developed a performance improvement of roughly 8%. Only marginally influence on fuel cell performance and degradation was observed in fuel switching experiments. A content of 22% CO2 had little influence on degradation, which could mainly be related to fuel dilution. Besides, micro‐computed tomography (µ‐CT) investigations revealed similar membrane and catalyst layer degradation for both kinds of fuel switching tests.
Characterization of C20 fullerene and its isolated C20‐nGen derivatives (n = 1‐5) by alternating germanium atom(s) in equatorial position: A DFT survey
Authors: Baei Mohammad T. , Koohi Maryam , Shariati Minoo
Published: February 2018

DFT calculations are applied to compare and contrast germanium atom(s) substituted C20‐nGen heterofullerenes with n = 1‐5, where the substitution is completely isolated from each other by means of one carbon atom in equatorial position. The structural stabilities, geometry, and electronic properties of C20 and its heterofullerene derivatives are compared and contrasted at M062X/6‐311++G**, B3LYP/AUG‐cc‐pVTZ, B3LYP/6‐311++G**, B3LYP/6‐311+G*, and B3PW91/6‐311++G** levels of theory. Vibrational frequency analysis shows that all of the heterofullerenes are real minima. Contrary to identical bonds in C20, contractions of C=C double bonds are encountered at the expense of longer C―Ge bonds in C20‐nGen. In contrast to previous reports on silicon doped heterofullerenes, none of the computed heterofullerenes collapses to open cage structures. Successive Ge doping on C20 induces more positive atomic charge on Ge atoms and more negative charge on C atoms. High charge transfer on the surfaces of our stable heterofullerenes provokes further investigations on their possible application for hydrogen storage. As to band gap, binding energy, heat of atomization per carbon, nucleus‐independent chemical shift, aromaticity, and the smallest vibrational frequency C19Ge immerges with the highest value. The reactivity in terms of ionization potential, nucleophilicity, electrophilicity, hardness, softness, maximum electronic charge, and proton affinity issues predicts C19Ge as the most stable heterofullerene against electronic excitation.
Supine positioning for the subscapular system of flaps: A pictorial essay
Authors: Eskander Antoine , Kang Stephen Y. , Ozer Enver , Agrawal Amit , Carrau Ricardo , Rocco James W. , Teknos Theodoros N. , Old Matthew O.
Published: February 2018

Background

This pictorial essay demonstrates a modification to the positioning, prepping, and draping technique for the subscapular system of flaps allowing the patient to be placed supine and without the need for a second assistant during the harvest or closure.

Methods and Results

We performed a literature review focusing on the positioning of the patient during the harvest of the subscapular system of flaps. A supine modification harvest prepping, draping, and position is then described in pictorial essay format. The technique is made possible with the use of a Mayo stand to position the arm.

Discussion

A literature review demonstrates limited description of nonlateral decubitus position harvest of the scapular flap. A novel positioning technique is described in pictorial essay format to demonstrate the ease and feasibility without the need for a second assistant during the case, an important goal in the era of limited resident duty hours.
Do you know your guidelines? Diagnosis and management of cutaneous head and neck melanoma
Authors: Ow Thomas J. , Grethlein Sara Jo , Schmalbach Cecelia E. ,   The Education Committee of the American Head and Neck Society (AHNS)
Published: February 2018

The following article is the next installment of the series “Do You Know Your Guidelines?” presented by the Education Committee of the American Head and Neck Society. Guidelines for the prevention, diagnosis, workup, and management of cutaneous melanoma are reviewed in an evidence‐based fashion.
Transient elastography is useful in diagnosing biliary atresia and predicting prognosis after hepatoportoenterostomy
Authors: Wu Jia‐Feng , Lee Chee‐Seng , Lin Wen‐Hsi , Jeng Yung‐Ming , Chen Huey‐Ling , Ni Yen‐Hsuan , Hsu Hong‐Yuan , Chang Mei‐Hwei
Published: February 2018

We investigated the utility of transient elastography (TE) for diagnosing biliary atresia (BA) in cholestatic infants and predicting the outcome of BA. Forty‐eight cholestatic infants (9‐87 days of age) with direct bilirubin level >1 mg/dL were enrolled. Liver stiffness measurement (LSM) by TE was performed during the cholestasis workup, and 15 subjects were diagnosed as BA. We assessed liver histology using liver biopsies from 36 subjects and graded fibrosis status using the METAVIR score. BA infants had significantly higher LSM values and METAVIR scores than non‐BA cholestatic infants. A receiver operating characteristic (ROC) curve analysis showed that an LSM >7.7 kPa was predictive of BA among cholestatic infants (sensitivity = 80%; specificity = 97%; area under the curve [AUC] = 85.3%; P = 0.0001). Cholestatic infants with an LSM >7.7 kPa were more likely to be diagnosed with BA (odds ratio [OR] = 128; P < 0.001). Very early measurement of LSM after hepatoportoenterostomy (HPE) is associated with occurrence of thrombocytopenia, splenomegaly, and esophageal varices 6 months post‐HPE. Five of the BA subjects were awaiting or had received liver transplantation (LT), and they had a significantly higher LSM measured 1 week post‐HPE than that in the other BA subjects (26.0 vs. 10.8 kPa; P = 0.006). A Cox proportional analysis demonstrated that the need for LT was significantly higher in BA subjects with LSM >16 kPa measured 1 week post‐HPE than other BA subjects (hazard ratio [HR] = 10.16; P = 0.04). Conclusion: LSM assessment during the workup of cholestatic infants may facilitate the diagnosis of BA. LSM post‐HPE may predict complications and the need for early LT in infants with BA. (Hepatology 2018).
Clinical, pathological, and biological characterization of Richter syndrome developing after ibrutinib treatment for relapsed chronic lymphocytic leukemia
Authors: Innocenti Idanna , Rossi Davide , Trapè Giulio , Autore Francesco , Larocca Luigi Maria , Gomes Vincenzo , Cerri Michaela , Falcucci Paolo , Sica Simona , Gaidano Gianluca , Laurenti Luca
Published: February 2018

Richter syndrome, a transformation of chronic lymphocytic leukemia (CLL) into a diffuse large B‐cell lymphoma, is a rare complication of patients treated with chemo‐immunotherapy. Richter syndrome might be both clonally related or unrelated to the underlying CLL and often showed mutations of the TP53 and NOTCH1 genes. Recently, ibrutinib was approved for patients with relapsed/refractory CLL or for untreated CLL patients with del 17p or TP53 mutation. The clinical picture, pathology, and genetics of Richter transformation after IBR treatment are largely unknown. Here, we report 2 cases of Richter transformation after Ibrutinib treatment. As just reported by previous report, Richter syndrome developing after ibrutinib therapy lacked resistance mutations of the BTK and PLCG2 genes, which are clonally related to the pre‐existent CLL phase representing transformation from CLL. Richter syndrome after ibrutinib seems to have some peculiar clinical findings as the bone marrow predilection, severe hypercalcemia, and a more aggressive outcome.
Lymphomas and thyroid: Bridging the gap
Authors: Mancuso Salvatrice , Carlisi Melania , Napolitano Mariasanta , Siragusa Sergio
Published: February 2018

The thyroid gland is often involved in the development of neoplastic diseases, including lymphoproliferative disorders. The aim of this paper is to provide a comprehensive overview of the multiple interactions between lymphoma and thyroid. Through an extensive research among the literature, the relationship between lymphomas and thyroid can be established at various levels, and the possible interconnections are here summarized in 5 points: (1) the greater risk of lymphoma development in some thyroid diseases; (2) the primary thyroid lymphoma, with focus on issues related to the diagnosis, differential diagnosis, and treatment; (3) the incidence of thyroid involvement in primitive nodal lymphomas or in extranodal lymphomas of the other sites; (4) thyroid changes after treatment of lymphoma, in relation to the effects of radiation therapy and immuno‐chemotherapy; (5) the incidental findings of thyroid changes, on imaging, in patients with lymphoma, without a direct involvement of the gland in malignant disease.

In conclusion, issues that until now have been dealt with separately will therefore be analyzed in a unique paper, allowing a global view of the topic and emphasizing the need of a multidisciplinary approach. Future learning areas in this topic mainly relate to rapidly increasing the knowledge of imaging studies together with expanding the armamentarium of novel biological and targeting agents in lymphoma patients.
MATERNAL DEPRESSION AND THE DEVELOPMENT OF EXECUTIVE FUNCTION AND BEHAVIOR PROBLEMS IN HEAD START: INDIRECT EFFECTS THROUGH PARENTING
Authors: Baker Claire E.
Published: February 2018

The present study used a large, nationally representative sample of Head Start children (N=3,349) from the Family and Child Experiences Survey of 2009 (FACES) to examine associations among maternal depression (measured when children were ˜36 months old) and children's executive function (EF) and behavior problems (measured when children were ˜48 months old). Preliminary analyses revealed that 36% of mothers in the sample had clinically significant levels of depressive symptoms. Furthermore, a path analysis with demographic controls showed a mediation effect that was significant and quite specific; mother‐reported warmth (and not mother–child reading) mediated the path between maternal depression, children's EF, and behavior problems. Findings provide empirical support for a family process model in which warm, sensitive parenting supports children's emerging self‐regulation and reduces the likelihood of early onset behavior problems in families in which children are exposed to maternal depression.