bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical cell disruption of microalgae for investigating the effects of degree of disruption on hydrocarbon extraction
Authors: Tsutsumi Shun , Yokomizo Madona , Saito Yasuhiro , Matsushita Yohsuke , Aoki Hideyuki
Published: April 2017

The colonial microalga, Botryococcus braunii, produces and stores hydrocarbons in membranes and in colonies. Although hydrocarbons in B. braunii could easily be extracted for biofuel production, yields are actually poor without energy‐intensive pretreatment such as thermal drying. To develop extraction methods without drying, we applied the mechanical cell disruption to wet B. braunii using either a high‐pressure homogenizer, a bead mill, or a circulating particle disruptor (Jet‐Paster) and examined the relationships between the extent of cell and/or colony disruption and extracted hydrocarbon yields using n‐hexane. When the number of particles over 20 μm classified as colonies, decreased after each treatment, the hydrocarbon yields of samples treated (over 20%) were much larger than those without treatments (under 5%). Thus, the colony disruption may increase hydrocarbon yields by enhancing n‐hexane penetration to the colony. Although the degree of disruption on the Jet‐Paster treatment was the lowest (2.2–9.3%) and that of sample treated by the homogenizer was the highest (27–55%), extracted hydrocarbon yields were improved in both treatments. The facts indicate that disrupting large colonies into small colonies improves hydrocarbon recovery, and the fractionation of cells is not needed for hydrocarbon extraction from B. braunii. © 2017 Curtin University of Technology and John Wiley & Sons, Ltd.
One‐step synthesis of corn starch urea based acrylate superabsorbents
Authors: Liu Ting Guo , Wang Yun Tao , Guo Jun , Liu Tian Bao , Wang Xin , Li Bin
Published: April 2017

A one‐step synthesis procedure for starch‐based acrylate superabsorbent polymers was proposed. The reaction conditions that may affect the water absorption capacity were discussed. A transparent gel‐like polymer containing urea (USAP) was successfully obtained by dissolving starch in a NaOH solution without further gelatinizing processing and using AA directly without prior neutralization. Urea was used as the nitrogen source and pore‐forming agent to improve the performance of the USAP. The optimum reaction conditions of the swelling ratio were also studied. A corn starch USAP was synthesized under the optimum conditions, and the water absorbency was 2704 ± 22, 561 ± 39, 100 ± 5, and 96 ± 4 g/g, respectively, in distilled water, running water, physiological saline, and artificial urine. Five kinds of starch‐based USAPs were also successfully prepared under the same conditions with excellent water absorption capacities, revealing that the one‐step method was a more convenient method for a potential industrial application pathway. The polymers were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, and thermogravimetric analysis. The results indicated that the PAA chains were successfully grafted onto the St backbone. However, the St molecular structure was not completely destroyed during the graft polymerization. The thermal analysis and nitrogen content results proved that urea was also involved in the graft copolymerization. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45175.
Performance Improvement of Fuel Cells Using Perturbation‐Based Extremum Seeking and Model Reference Adaptive Control
Authors: Dadkhah Tehrani Reza , Shabani Faridoon
Published: April 2017

Nowadays, fuel cells (FCs) are considered suitable alternative sources for electrical energy applications. One major challenge encountered in FCs is relevant to the performance of the maximum power point tracking (MPPT) under FC parameter changes and load variations. This challenge is due to the nonlinearity and time‐varying dynamics of FC systems. In this paper, the MPPT is studied in a system composed of a FC and a DC‐DC converter. To improve the performance of the MPPT, application of perturbation‐based extremum seeking (PES) and model reference adaptive control (MRAC) is proposed. This control scheme can efficiently handle the uncertainties in the FC as well as the load, through two control levels. The first level is PES utilized to adjust the duty cycle of the DC‐DC converter; and the second level is MRAC employed to achieve the desired dynamic response. Using the proposed control strategy, design and analysis of the control levels can be realized independently, which results in easy implementation. This is achieved due to considerable differences between the time constants of the control levels. The simulation results are utilized to confirm the effectiveness of the proposed scheme in response to the variations of FC parameters and load. Also, comparative studies with a combination of PES and PID controller are provided in the simulation.
A life cycle energy use and greenhouse gas emissions analysis of the corn stover feedstock supply system for cellulosic biorefineries
Authors: Shah Ajay , Darr Matt
Published: April 2017

Corn stover is the primary feedstock choice for most of the near‐term first‐generation cellulosic biorefineries in the Midwest with rated capacities between 76 and 114 million liters per year (MLPY). These biorefineries will require an annual feedstock supply of around 250–375 metric ton (t) to meet their feedstock demand. However, there is a dearth of studies based on sustainable ways to supply a vast quantity of feedstock to the biorefinery gate, thus this study focuses on stochastically evaluating the life‐cycle energy use and greenhouse gas emissions (GHGE) of the different components of corn stover based feedstock supply system of a 114 MLPY cellulosic biorefinery in the Midwest by using production‐scale experimental field data collected in Iowa. Different components of the supply chain considered includes corn stover harvesting in a large rectangular bale form, field collection, storage, handling and transportation. This study also evaluates the energy use and GHGE of nutrients removed from the field with collected stover. Average energy use, energy‐use ratio (EUR) and GHGE for this feedstock supply system of a Midwest‐based 114 MLPY biorefinery plant are estimated to be 1,502 MJ std. t−1, 21%, and 95.2 kg‐CO2e std. t−1, respectively. Nutrients removed during stover harvest shares 38 to 47% of the overall life‐cycle energy use and GHGE for the supply chain, followed by harvesting (~24–28%) and transportation (~23–27%). Life‐cycle GHGE and energy use are identified to be the most sensitive to the quantity of nitrogen removed, bale density, bale length, harvest rate, baler field efficiency and dry matter loss. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd
On Narrow Norms of Rationality and Questionable Data Analyses: A Comment on Jekel and Glöckner
Authors: Rieskamp Jörg
Published: April 2017

In many areas of psychology, it has been argued that people are equipped with a repertoire of strategies to solve the problems they face. Past work has also shown that in situations in which people receive feedback about the correctness of their inferences, substantial learning effects occur, such that simple heuristics that perform well in an environment also do well in describing people's inferences (e.g., Rieskamp, 2006; Rieskamp & Otto, 2006). This work has been challenged by Jekel and Glöcker (2016), who argued that the simple heuristic was compared with a weak competitor. In this work, I reply to this challenge by showing that the competing compensatory strategy is not a weak competitor on either normative or descriptive empirical grounds. I show that the conclusions of past work also hold when including—as suggested—additional compensatory strategies as competing models. The theoretical and empirical analysis demonstrates that the conclusions of Jekel and Glöckner rely on narrow theoretical assumptions and questionable reanalyses of past results. Copyright © 2017 John Wiley & Sons, Ltd.
Safe driving communication: A regulatory focus perspective
Authors: Craciun Georgiana , Shin Dongwoo , Zhang Jason Q.
Published: April 2017

This research article examines the effects of self‐regulation on adolescents' aggressive driving tendencies and their attitudes toward safe driving communication. Two experimental studies demonstrate that an individual's regulatory orientation is a good predictor of aggressive driving tendencies and that self‐regulation plays a moderating role on the effects of safe driving messages on recipients' attitudes. Specifically, the findings reveal that promotion‐oriented (vs. prevention‐oriented) individuals are more likely to demonstrate aggressive driving tendencies. In addition, promotion‐oriented individuals show more favorable attitudes toward gain‐framed safe driving messages than loss‐framed messages. Prevention‐oriented individuals show the opposite pattern. Implications for theory and practice are discussed.
Biochemical Characterization and Analyses of Polysialic‐Acid‐Associated Carrier Proteins and Genes in Piglets during Neonatal Development
Authors: Chen Yue , Ren He , Zhang Nai , Troy Frederic A. , Wang Bing
Published: April 2017

Polysialic acid plays a key role in cancer metastasis and neurodevelopment. Our aim was to determine the developmental gene‐expression profiles for the two polysialyltransferases ST8Sia II and ST8Sia IV, neural cell‐adhesion molecules (NCAMs), SynCAM 1, neuropilin‐2 (NRP2) and their polysialylated cognate glycans in different regions of the piglet brain during postnatal development. Our findings show that: 1) the cellular levels of mRNA coding for ST8Sia II and ST8Sia IV, NCAMs, SynCAM 1, NRP2 and polySia are age‐dependent and cell‐type‐specific during neonatal brain development, 2) there was a lack of correlation between abundance level of mRNA coding for ST8Sia II and ST8Sia IV and the abundance level of the post‐translation expression of polySia in all nine brain regions, 3) expression levels of polySia did not correlate with the levels of the carrier proteins NCAM‐140, SynCAM 1 and NRP2 in nine brain regions, and 4) the cellular abundance of ST8Sia II and ST8Sia IV in nine subregions of piglet brain is regulated at the level of translation/post‐translation, and not at the level of transcription. Collectively, our findings suggest that neuronal and glial cells within different regions of the brain have different transcriptional programs that can direct cell division at different rates based on the activity levels of ST8Sia II and ST8Sia IV and the level of their carrier proteins during neurodevelopment.
Synthesis and Reactivity of 2‐Arylquinazoline Halidoruthenacycles in Arylation Reactions
Authors: Kuzman Petra , Požgan Franc , Meden Anton , Svete Jurij , Štefane Bogdan
Published: April 2017

The synthesis of a range of new cyclometallated organoruthenium(II) complexes through the ortho‐C−H activation of the aryl group in 2‐aryl‐substituted quinazolines with [RuX2(p‐cymene)]2 is described. The beneficial effect of the carboxylate ligand on both the cyclometallation and the further arylation reaction step was demonstrated. Mechanistic studies reveal that bromide and iodide anions decelerate the arylation process by an in situ ligand exchange reaction. Additionally, a detailed NMR spectroscopy investigation was performed to explain some elementary steps in the arylation of 2‐(aryl)quinazoline halidoruthenacycles.
Hydrothermal Carbonization of Lignin with Vanillin as a Model Component
Authors: Curtze Jan Henning , Bär Fabian , Steffan Jörg , Dörr Timo , Vogel Herbert
Published: April 2017

Hydrothermal carbonization (HTC) is one possibility to concentrate energy of wet biomass in so‐called hydrochar. To design technical HTC reactors in a rational way, the reaction kinetics of the four main components of biomass, i.e., carbohydrates, lignin, fats/oils, and proteins, should be known. To determine the kinetics of hydrochar functionalization, initially an appropriate analytical method must be developed. In the presented experiments, the hydrochar obtained by HTC of vanillin is investigated by diffuse reflectance infrared (IR) Fourier transform spectroscopy (DRIFTS). In order to assign the IR bands in the DRIFT spectra to different functional groups, temperature‐programmed desorption (TPD) experiments are conducted, followed by a combination of DRIFTS and TPD. This TPD/DRIFT combination is applied as an analytical method to investigate the kinetics of hydrochar functionalization during HTC.
Fluorescence‐Lifetime Imaging and Super‐Resolution Microscopies Shed Light on the Directed‐ and Self‐Assembly of Functional Porphyrins onto Carbon Nanotubes and Flat Surfaces
Authors: Mao Boyang , Calatayud David G. , Mirabello Vincenzo , Kuganathan Navaratnarajah , Ge Haobo , Jacobs Robert M. J. , Shepherd Ashley M. , Ribeiro Martins José A. , Bernardino De La Serna Jorge , Hodges Benjamin J. , Botchway Stanley W. , Pascu Sofia I.
Published: April 2017

Functional porphyrins have attracted intense attention due to their remarkably high extinction coefficients in the visible region and potential for optical and energy‐related applications. Two new routes to functionalised SWNTs have been established using a bulky ZnII‐porphyrin featuring thiolate groups at the periphery. We probed the optical properties of this zinc(II)‐substituted, bulky aryl porphyrin and those of the corresponding new nano‐composites with single walled carbon nanotube (SWNTs) and coronene, as a model for graphene. We report hereby on: i) the supramolecular interactions between the pristine SWNTs and ZnII‐porphyrin by virtue of π–π stacking, and ii) a novel covalent binding strategy based on the Bingel reaction. The functional porphyrins used acted as dispersing agent for the SWNTs and the resulting nanohybrids showed improved dispersibility in common organic solvents. The synthesized hybrid materials were probed by various characterisation techniques, leading to the prediction that supramolecular polymerisation and host–guest functionalities control the fluorescence emission intensity and fluorescence lifetime properties. For the first time, XPS studies highlighted the differences in covalent versus non‐covalent attachments of functional metalloporphyrins to SWNTs. Gas‐phase DFT calculations indicated that the ZnII‐porphyrin interacts non‐covalently with SWNTs to form a donor–acceptor complex. The covalent attachment of the porphyrin chromophore to the surface of SWNTs affects the absorption and emission properties of the hybrid system to a greater extent than in the case of the supramolecular functionalisation of the SWNTs. This represents a synthetic challenge as well as an opportunity in the design of functional nanohybrids for future sensing and optoelectronic applications.
Soluble Porous Coordination Frameworks Constructed from Inorganic Nanoparticles as Homogenized Heterogeneous Photocatalysts for Suzuki Coupling Reactions under Near‐Infrared Light
Authors: Luo Yuting , Peng Yong , Liu Weisheng , Chen Fengjuan , Wang Baodui
Published: April 2017

Self‐assembly has emerged as a promising method to control the structure and properties of ensembles of inorganic nanoparticles (NPs) for exploiting their collective effects. However, the rational assembly of inorganic NPs into soluble porous architectures for use as homogenized heterogeneous catalysts has been less studied. Herein, it is shown that inorganic NPs can be used for the assembly of soluble porous coordination frameworks (PCFs) by atom‐scale interfacial coordination‐driven assembly. Owing to their large pore size, high dispersity in solution, strong absorption in the near‐infrared (NIR) range, and long‐lived electron–hole pair, the obtained soluble frameworks could serve as a platform for homogenized heterogeneous photocatalysts, which exhibited excellent activity, high apparent quantum efficiency, and recyclability in the catalysis of the noble‐metal‐free Suzuki coupling reactions under NIR light at room temperature. Moreover, PCF catalysts can be reused more than five times without significant loss of activity, which indicates long‐term stability. The present strategy to fabricate soluble porous nanostructures opens a new chemical toolbox for homogenized heterogeneous catalysts and may bring new inspiration to photocatalysis.
Dynamic Iminoboronate‐Based Boroxine Chemistry for the Design of Ambient Humidity‐Sensitive Self‐Healing Polymers
Authors: Delpierre Sébastien , Willocq Bertrand , De Winter Julien , Dubois Philippe , Gerbaux Pascal , Raquez Jean‐Marie
Published: April 2017

Developing intrinsic self‐healing polymeric materials is of great interest nowadays to extend material lifetime and/or prevent the replacement of damaged pieces. Spontaneously humidity‐sensitive healable polymer network built around dynamic covalent B−O bonds was templated by using iminoboronate‐based boroxine derivatives. Taking advantage of the dynamic boroxine/boronic acid equilibrium and iminoboronate chemistry, it is possible to construct polymeric materials able to self‐heal without requiring any energy‐demanding external activation. Interestingly, this novel family of iminoboronate adduct‐based materials can be readily produced by a relatively simple and straightforward synthesis between boronic acid and diamine‐based compounds, paving the way to coatings that are self‐healable at ambient humidity.
N‐Acetonitrile Functionalized Nitropyrazoles: Precursors to Insensitive Asymmetric N‐Methylene‐C Linked Azoles
Authors: Kumar Dheeraj , Imler Gregory H. , Parrish Damon A. , Shreeve Jean'ne M.
Published: April 2017

Properties of energetic compounds obtained by linking energetic pyrazoles to tetrazoles by means of N‐methylene‐C bridges can be fine‐tuned. Reactions of pyrazole derivatives with chloroacetonitrile followed by conversion of the cyano group to tetrazole using click reactions in the presence of zinc chloride result in asymmetric N‐methylene‐C bridged azole‐based energetic compounds. All the compounds were thoroughly characterized by IR and NMR [1H, 13C {1H}, 15N] spectroscopy, elemental analysis, and differential scanning calorimetry (DSC), and for two compounds, further supported by single‐crystal X‐ray diffraction studies. Heats of formation and detonation performances were calculated using Gaussian 03 and EXPLO5 v6.01 programs, respectively. Initial studies show that this new approach is promising for synthesizing less sensitive energetic compounds with fine‐tuned properties.
Thiocarbohydrates on Gold Nanoparticles: Strong Influence of Stereocenters on Binding Affinity and Interparticle Forces
Authors: Fudickar Werner , Pavashe Prashant , Linker Torsten
Published: April 2017

Carbohydrates carrying thiol groups at the C‐2 position have been attached to gold nanoparticles (AuNPs) with stereocenters in close proximity to the surface for the first time. Their configurations can be clearly distinguished by the tendency of particle aggregation. AuNP surface plasmon resonance (SPR), X‐ray photoelectron spectroscopy (XPS), and IR spectroscopy indicate that the thiocarbohydrates replace citrate molecules at different rates, causing aggregation and eventually precipitation. A quantitative formulation of this aggregation process shows that reactivities can vary by several magnitudes. Adsorption isotherms and kinetics also demonstrate that the number of thiocarbohydrates varies by a factor of two. Molecular mechanics force field (MMFF) calculations reveal their relative orientations. Based on these models, the different binding behavior can be ascribed to attractive van der Waals forces and hydrogen bonds. Such interactions occur either between the carbohydrate and AuNPs, by lateral intermolecular forces at the surface, or by interparticle attraction, in analogy to cell‐surface carbohydrates of biological recognition systems. Aggregation of NPs therefore act as an indicator to differentiate between various carbohydrates with defined configurations.
Catalytic Mechanism of Salicylate Dioxygenase: QM/MM Simulations Reveal the Origin of Unexpected Regioselectivity of the Ring Cleavage
Authors: Roy Subhendu , Kästner Johannes
Published: April 2017

Salicylate 1,2‐dioxygenase (SDO) was the first enzyme discovered, in the family of iron dioxygenases, to catalyze the ring cleavage of a monohydroxylated aromatic compound, salicylate, without a proton donor. Salicylate is not electron‐rich like the familiar dihydroxy or aromatic substrates with an electron‐donating group that are utilized in the well‐known dioxygenases. SDO carries out the intramolecular C−C bond cleavage in salicylate bearing the OH and COOH groups with high regioselectivity in comparison with the extradiol and intradiol dioxygenases. The catalytic cleavage of a nonactivated substrate like salicylate that lacks an electron‐donating group, also in the absence of a proton source, raises many puzzling questions about the oxy intermediates in the reaction pathway of dioxygenase enzymes in general. To answer these fundamental queries, we have investigated the full catalytic mechanism of SDO by a combination of quantum mechanics and molecular mechanics (QM/MM) calculations. Herein, our QM/MM study has several unexpected and interesting implications for the mechanistic pathway of SDO in comparison to the experimental observations. Importantly, it unravels the basis for the unexpected “intra”‐cleavage regioselectivity in SDO. Ostensibly a similar alkylperoxo intermediate is formed in SDO much like in the extradiol and intradiol dioxygenases. In stark contrast to the two diol enzymes, the O−O bond breaking leads to an unprotonated gem‐hydroxy carboxylate intermediate, a paradigm analogue of the elusive gem diol intermediate. This unprotonated gem‐hydroxy carboxylate intermediate exclusively dictates the C−C cleavage regiospecificity in SDO, which is unprecedented in the family of dioxygenases. It forms a seven‐membered lactone species, which eventually forms the ring‐cleavage final product by incorporation of two oxygen atoms in the salicylate. Thus, our computational study unravels a detailed reaction pathway of the oxidative cleavage of salicylate without a proton source by identifying the hitherto elusive intermediates in the catalytic cycle of SDO with testable predictions. Moreover, we describe the atomistic origin of the new catalytic role of Arg127 in the catalysis and regioselectivity of SDO. It also rationalizes the formation of a side product without invoking a dioxetane intermediate. This study is important from a fundamental perspective and opens up a new window in the mechanism of the family of dioxygenase enzymes.
Indium(III)‐catalyzed Aza‐Conia‐Ene Reaction for the Synthesis of Indolizines
Authors: Meazza Marta , Leth Lars A. , Erickson Jeremy D. , Jørgensen Karl Anker
Published: April 2017

A new indium(III)‐catalyzed reaction for the synthesis of a series of indolizine scaffolds has been developed. This methodology was highly efficient, allowing a low catalyst loading of 2 mol % (down to 0.5 mol %) and rendering the products in high yields through a 5‐exo‐dig aza‐Conia‐ene reaction. Furthermore, the possibility of incorporating an electrophile into the generated pyrrolidone ring in a one‐pot synergistic fashion was demonstrated. Finally, based on experimental observations, a mechanism proposal was outlined.
High‐throughput cell mechanical phenotyping for label‐free titration assays of cytoskeletal modifications
Authors: Golfier Stefan , Rosendahl Philipp , Mietke Alexander , Herbig Maik , Guck Jochen , Otto Oliver
Published: April 2017

The mechanical fingerprint of cells is inherently linked to the structure of the cytoskeleton and can serve as a label‐free marker for cell homeostasis or pathologic states. How cytoskeletal composition affects the physical response of cells to external loads has been intensively studied with a spectrum of techniques, yet quantitative and statistically powerful investigations in the form of titration assays are hampered by the low throughput of most available methods. In this study, we employ real‐time deformability cytometry (RT‐DC), a novel microfluidic tool to examine the effects of biochemically modified F‐actin and microtubule stability and nuclear chromatin structure on cell deformation in a human leukemia cell line (HL60). The high throughput of our method facilitates extensive titration assays that allow for significance assessment of the observed effects and extraction of half‐maximal concentrations for most of the applied reagents. We quantitatively show that integrity of the F‐actin cortex and microtubule network dominate cell deformation on millisecond timescales probed with RT‐DC. Drug‐induced alterations in the nuclear chromatin structure were not found to consistently affect cell deformation. The sensitivity of the high‐throughput cell mechanical measurements to the cytoskeletal modifications we present in this study opens up new possibilities for label‐free dose‐response assays of cytoskeletal modifications.
Neuronal distribution of tyramine and the tyramine receptor AmTAR1 in the honeybee brain
Authors: Thamm Markus , Scholl Christina , Reim Tina , Grübel Kornelia , Möller Karin , Rössler Wolfgang , Scheiner Ricarda
Published: April 2017

Tyramine is an important neurotransmitter, neuromodulator, and neurohormone in insects. In honeybees, it is assumed to have functions in modulating sensory responsiveness and controlling motor behavior. Tyramine can bind to two characterized receptors in honeybees, both of which are coupled to intracellular cAMP pathways. How tyramine acts on neuronal, cellular and circuit levels is unclear. We investigated the spatial brain expression of the tyramine receptor AmTAR1 using a specific antibody. This antibody detects a membrane protein of the expected molecular weight in western blot analysis. In honeybee brains, it labels different structures which process sensory information. Labeling along the antennal nerve, in projections of the dorsal lobe and in the gnathal ganglion suggest that tyramine receptors are involved in modulating gustatory and tactile perception. Furthermore, the ellipsoid body of the central complex and giant synapses in the lateral complex show AmTAR1‐like immunoreactivity (AmTAR1‐IR), suggesting a role of this receptor in modulating sky‐compass information and/or higher sensor‐motor control. Additionally, intense signals derive from the mushroom bodies, higher‐order integration centers for olfactory, visual, gustatory and tactile information. To investigate whether AmTAR1‐expressing brain structures are in vicinity to tyramine releasing sites, a specific tyramine antibody was applied. Tyramine‐like labeling was observed in AmTAR1‐IR positive structures, although it was sometimes weak and we did not always find a direct match of ligand and receptor. Moreover, tyramine‐like immunoreactivity was also found in brain regions without AmTAR1‐IR (optic lobes, antennal lobes), indicating that other tyramine‐specific receptors may be expressed there.
Population Pharmacokinetics of Liposomal Irinotecan in Patients With Cancer
Authors: Adiwijaya BS , Kim J , Lang I , Csõszi T , Cubillo A , Chen J‐S , Wong M , Park JO , Kim JS , Rau KM , Melichar B , Gallego JB , Fitzgerald J , Belanger B , Molnar I , Ma WW
Published: April 2017

Nanoliposomal irinotecan (nal‐IRI) is a liposomal formulation of irinotecan with a longer half‐life (t1/2), higher plasma total irinotecan (tIRI), and lower SN‐38 maximum concentration (Cmax) compared with nonliposomal irinotecan. Population pharmacokinetic (PK) analysis of nal‐IRI was performed for tIRI and total SN‐38 (tSN38) using patient samples from six studies. PK‐safety association was evaluated for neutropenia and diarrhea in 353 patients. PK‐efficacy association was evaluated from a phase III study in pancreatic cancer NAPOLI1. Efficacy was associated with longer duration of unencapsulated SN‐38 (uSN38) above a threshold and higher Cavg of tIRI, tSN38, and uSN38. Neutropenia was associated with uSN38 Cmax and diarrhea with tIRI Cmax. Baseline predictive factors were race, body surface area, and bilirubin. Analysis identified PK factors associated with efficacy, safety, and predictive baseline factors. The results support the benefit of nal‐IRI dose of 70 mg/m2 (free‐base; equivalent to 80 mg/m2 salt base) Q2W over 100 mg/m2 Q3W.
Effect of Donor Strength and Bulk on Thieno[3,4‐b]‐pyrazine‐Based Panchromatic Dyes in Dye‐Sensitized Solar Cells
Authors: Liyanage Nalaka P. , Cheema Hammad , Baumann Alexandra R. , Zylstra Alexa R. , Delcamp Jared H.
Published: April 2017

Near‐infrared‐absorbing organic dyes are critically needed in dye‐sensitized solar cells (DSCs). Thieno[3,4‐b]pyrazine (TPz) based dyes can access the NIR spectral region and show power conversion efficiencies (PCEs) of up to 8.1 % with sunlight being converted at wavelengths up to 800 nm for 17.6 mA cm−2 of photocurrent in a co‐sensitized DSC device. Precisely controlling dye excited‐state energies is critical for good performances in NIR DSCs. Strategies to control TPz dye energetics with stronger donor groups and TPz substituent choice are evaluated here. Additionally, donor size influence versus dye loading on TPz dyes is analyzed with respect to the TiO2 surface protection designed to prevent recombination of electrons in TiO2 with the redox shuttle. Importantly, the dyes evaluated were demonstrated to work well with low Li+ concentration electrolytes, with iodine and cobalt redox shuttle systems, and efficiently as part of co‐sensitized devices.
Secure multi‐factor remote user authentication scheme for Internet of Things environments
Authors: Dhillon Parwinder Kaur , Kalra Sheetal
Published: April 2017

Because of the exponential growth of Internet of Things (IoT), several services are being developed. These services can be accessed through smart gadgets by the user at any place, every time and anywhere. This makes security and privacy central to IoT environments. In this paper, we propose a lightweight, robust, and multi‐factor remote user authentication and key agreement scheme for IoT environments. Using this protocol, any authorized user can access and gather real‐time sensor data from the IoT nodes. Before gaining access to any IoT node, the user must first get authenticated by the gateway node as well as the IoT node. The proposed protocol is based on XOR and hash operations, and includes: (i) a 3‐factor authentication (ie, password, biometrics, and smart device); (ii) mutual authentication; (iii) shared session key; and (iv) key freshness. It satisfies desirable security attributes and maintains acceptable efficiency in terms of the computational overheads for resource constrained IoT environment. Further, the informal and formal security analysis using AVISPA proves security strength of the protocol and its robustness against all possible security threats. Simulation results also prove that the scheme is secure against attacks.
Response of biofilm growth to experimental warming in a temperate stream
Authors: Delgado Cristina , Almeida Salomé F.P. , Elias Carmen L. , Ferreira Verónica , Canhoto Cristina
Published: April 2017

Biofilm is an important component of small streams, and it is highly sensitive to variations in water temperature. Therefore, it is expectable that the warming predicted for this century will be reflected in its communities. In this study, we investigated the effects of experimental warming on biofilm growth in a small forest stream in Central Portugal. The stream was longitudinally divided in two halves, both at ambient temperature during ambient period; the following months (warmed period), one stream half remained at ambient temperature (control half) and the other half was experimentally warmed by ~3 °C (experimental half), following a before‐after control‐impact design. Biofilm variables (biomass, chlorophyll‐a and chlorophyll‐c concentrations, autotrophic index, and diatom density) were determined from epilithic samples collected from both stream halves three times during the ambient period and five times during the warmed period. The experimental warming led to a significant increase in biomass, chlorophyll‐a, chlorophyll‐c concentration, and diatom density, especially in the winter months. Future warming, especially during the colder months, may thus stimulate biofilm growth, which may strengthen the autotrophic pathways of these systems traditionally based on detritus.
Enhancing the Magnetic Heating Capacity of Iron Oxide Nanoparticles through Their Postproduction Incorporation into Iron Oxide–Gold Nanocomposites
Authors: Bell Gavin , Bogart Lara K. , Southern Paul , Olivo Malini , Pankhurst Quentin A. , Parkin Ivan P.
Published: April 2017

Invited for the cover of this issue is the group of Ivan P. Parkin and Quentin A. Pankhurst from University College London, UK, in collaboration with Malini Olivo from A*STAR Singapore Bioimaging Consortium. The cover image shows how nanocomposite particles heat up as a result of magnetic hyperthermia when an external magnetic field is applied.
Design of Radioiodinated Pharmaceuticals: Structural Features Affecting Metabolic Stability towards in Vivo Deiodination
Authors: Cavina Lorenzo , van der Born Dion , Klaren Peter H. M. , Feiters Martin C. , Boerman Otto C. , Rutjes Floris P. J. T.
Published: April 2017

Radioiodinated pharmaceuticals are convenient tracers for clinical and research investigations because of the relatively long half‐lives of radioactive iodine isotopes (i.e., 123I, 124I, and 131I) and the ease of their chemical insertion. Their application in radionuclide imaging and therapy may, however, be hampered by poor in vivo stability of the C–I bond. After an overview of the use of iodine in biology and nuclear medicine, we present here a survey of the catabolic pathways for iodinated xenobiotics, including their biodistribution, accumulation, and biostability. We summarize successful rational improvements in the biostability and conclude with general guidelines for the design of stable radioiodinated pharmaceuticals. It appears to be necessary to consider the whole molecule, rather than the radioiodinated fragment alone. Iodine radionuclides are generally retained in vivo on sp2 carbon atoms in iodoarenes and iodovinyl moieties, but not in iodinated heterocycles or on sp3 carbon atoms. Iodoarene substituents also have an influence, with increased in vivo deiodination in the cases of iodophenols and iodoanilines, whereas methoxylation and difluorination improve biostability.
Recent Progress in Decarboxylative Oxidative Cross‐Coupling for Biaryl Synthesis
Authors: Perry Gregory J. P. , Larrosa Igor
Published: April 2017

The beginning of the 21st century has seen tremendous growth in the field of decarboxylative activation. Benzoic acid derivatives are now recognised as atom‐economic alternatives to traditional cross‐coupling partners, and they also benefit from being inexpensive, readily available and shelf‐stable reagents. In this microreview we discuss recent developments in the coupling of benzoic acid derivatives either with an arene or with a second benzoic acid derivative, a process often termed decarboxylative oxidative cross‐coupling. These procedures offer great promise for the development of highly selective and atom‐economic cross‐couplings.
Induction of micronuclei and cell cycle arrest by some tri‐ and tetrachlorobiphenyls in mammalian cells deficient in xenobiotic‐metabolizing enzymes
Authors: Wang Haiyan , Wei Liwen , Wu Yifan , Jia Hansi , Jiang Hao , Liu Yungang
Published: April 2017

Polychlorinated biphenyls (PCBs) are persistent organic pollutants with continued public health concerns. The lower chlorinated biphenyls are supposed to be mutagenic following metabolic activation. However, in a preliminary study, we recently observed induction of micronuclei by several PCBs in a subclone of Chinese hamster V79 cell line, V79‐Mz, which is deficient in xenobiotic‐metabolizing enzyme activities. In this study, metabolism‐free genotoxicity of PCBs was investigated, using 10 tri‐ and tetrachlorobiphenyls, in V79, V79‐Mz, and human hepatoma (HepG2) cell lines. Among the four tetrachlorobiphenyls, 2,4,4′,5‐ and 2,3′4,4′‐tetrachlorobiphenyl—both having a noncoplanar configuration—induced micronuclei in V79‐Mz cells, while their coplanar analogs 3,4,4′,5‐ and 3,3′,4,4′‐tetrachlorobiphenyl were inactive. Furthermore, 2,3,3′‐ (PCB 20) and 2,3,4′‐trichlorobiphenyl (PCB 22) started to induce micronuclei in V79‐Mz cells at 10 μM and higher concentrations, demonstrating more potent effects than observed with 2,2′,3‐, 2,2′,4‐, 2,2′,5, and 2,4,4′‐trichlorobiphenyl. As representative compounds, PCB 20 and 22 induced micronuclei in relatively high concentrations in HepG2 cells (p53‐proficient), though they did not induce Hprt gene mutations in V79‐Mz cells. PCB 20 and 22 increased mitotic index and induced cell cycle arrest at the G2/M phase, with effects more potent in V79‐Mz than in V79 cells. This study suggests that 2,3,4′‐ and 2,3,3′‐substituted PCBs are micronuclei inducers and G2/M arresters among a number of trichlorobiphenyls in mammalian cell lines, though with potency lower than that observed recently in V79‐derived cells expressing human CYP2E1. Similarly, some noncoplanar tetrachlorobiphenyls possess metabolism‐independent chromosome‐damaging potentials. Environ. Mol. Mutagen. 58:199–208, 2017. © 2017 Wiley Periodicals, Inc.
Comparative tumor promotion assessment of e‐cigarette and cigarettes using the in vitro Bhas 42 cell transformation assay
Authors: Breheny Damien , Oke Oluwatobiloba , Pant Kamala , Gaça Marianna
Published: April 2017

In vitro cell transformation assays (CTA) are used to assess the carcinogenic potential of chemicals and complex mixtures and can detect nongenotoxic as well as genotoxic carcinogens. The Bhas 42 CTA has been developed with both initiation and promotion protocols to distinguish between these two carcinogen classes. Cigarette smoke is known to be carcinogenic and is positive in in vitro genotoxicity assays. Cigarette smoke also contains nongenotoxic carcinogens and is a tumour promoter and cocarcinogen in vivo. We have combined a suite of in vitro assays to compare the relative biological effects of new categories of tobacco and nicotine products with traditional cigarettes. The Bhas promotion assay has been included in this test battery to provide an in vitro surrogate for detecting tumor promoters. The activity of an electronic cigarette (e‐cigarette; Vype ePen) was compared to that of a reference cigarette (3R4F) in the promotion assay, using total particulate matter (TPM)/aerosol collected matter (ACM) and aqueous extracts (AqE) of product aerosol emissions. 3R4F TPM was positive in this assay at concentrations ≥6 µg/mL, while e‐cigarette ACM did not have any promoter activity. AqE was found to be a lesssuitable test matrix in this assay due to high cytotoxicity. This is the first study to use the Bhas assay to compare tobacco and nicotine products and demonstrates the potential for its future application as part of a product assessment framework. These data add to growing evidence suggesting that e‐cigarettes may provide a safer alternative to traditional cigarettes. Environ. Mol. Mutagen. 58:190–198, 2017. © 2017 The Authors. Environmental and Molecular Mutagenesis Published by Wiley Periodicals, Inc.
Investigation of the Cofiring of Methane and Biosyngas for Combined Cooling, Heating, and Power Generation with Zero Carbon Dioxide Emissions
Authors: Li Wenshu , Shen Jianfei , Zhang Ge
Published: April 2017

A new chemical looping combustion (CLC) of biosyngas and methane in a system with combined cooling, heating, and power (CCHP) is presented. The aim of the integration of CLC into the CCHP system is to obtain zero CO2 emissions and to reduce exergy destruction within the combustion process. With the increase in the biomass‐to‐methane mass ratio from 0 to 1 (referred to as 100 %), the total energy output increases from 637.17 to 746.62 kW, and there is a simultaneous reduction of both the energy and exergy efficiencies from 91.70 to 82.10 % and from 43.32 to 37.84 %, respectively. However, the primary energy savings ratio benefits from an increase of the biomass mass ratio (from 0 to 1) and increases from 42.80 to 46.36 %. Furthermore, a conventional CCHP system is developed and simulated for comparison. To discuss the feasibility of this process, the effect of the gas conversion ratio in the CLC system on the overall efficiency was analyzed and the autothermal operation strategy of CLC was considered.
Anthropogenic influences on groundwater in the vicinity of a long‐lived radioactive waste repository
Authors: Thomas Matthew A. , Kuhlman Kristopher L. , Ward Anderson L.
Published: April 2017

The groundwater flow system in the Culebra Dolomite Member (Culebra) of the Permian Rustler Formation is a potential radionuclide release pathway from the Waste Isolation Pilot Plant (WIPP), the only deep geological repository for transuranic waste in the United States. In early conceptual models of the Culebra, groundwater levels were not expected to fluctuate markedly, except in response to long‐term climatic changes, with response times on the order of hundreds to thousands of years. Recent groundwater pressures measured in monitoring wells record more than 25 m of drawdown. The fluctuations are attributed to pumping activities at a privately owned well that may be associated with the demand of the Permian Basin hydrocarbon industry for water. The unprecedented magnitude of drawdown provides an opportunity to quantitatively assess the influence of unplanned anthropogenic forcings near the WIPP. Spatially variable realizations of Culebra saturated hydraulic conductivity and specific storage were used to develop groundwater flow models to estimate a pumping rate for the private well and investigate its effect on advective transport. Simulated drawdown shows reasonable agreement with observations (average Model Efficiency coefficient = 0.7). Steepened hydraulic gradients associated with the pumping reduce estimates of conservative particle travel times across the domain by one half and shift the intersection of the average particle track with the compliance boundary by more than 2 km. The value of the transient simulations conducted for this study lies in their ability to (a) improve understanding of the Culebra groundwater flow system and (b) challenge the notion of time‐invariant land use in the vicinity of the WIPP.
Fractal characteristics of the microvascular network: A useful index to assess vascularization level of porous silk fibroin biomaterial
Authors: Zhan Kuihua , Bai Lun , Wu Qinqin , Lei Derong , Wang Guangqian
Published: April 2017

The neovascularization of biomaterials for tissue engineering is not only related to growth of capillaries but also involves appropriate hierarchy distribution of the microvessels. In this study, we proposed hierarchy distribution contrast method which can assess vascular transport capacity, in order to examine the hierarchy distribution of the neovessels during vascularization of the porous silk fibroin biomaterials implanted into rats and its evolution. The results showed that the fractal characteristics appeared toward the end of the vascularization stages, and the structure of the microvascular network after 3 weeks of implantation was similar to the fractal microvascular tree with bifurcation exponent x = 3 and fractal dimension D = 1.46, which became a sign of maturation of the regenerative vasculature. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2276–2290, 2017.
Fabrication and characterization of chitosan, polyvinylpyrrolidone, and cellulose nanowhiskers nanocomposite films for wound healing drug delivery application
Authors: Hasan Abshar , Waibhaw Gyan , Tiwari Sakshi , Dharmalingam K. , Shukla I. , Pandey Lalit M.
Published: April 2017

This study describes the preparation of composite film using chitosan (CS) and polyvinylpyrrolidone (PVP) with incorporated cellulose nanowhiskers (CNWs) for drug delivery application. CNWs were prepared by acid hydrolysis of cellulose with sulfuric acid. Field emission scanning electron microscopy studies revealed nanofibrous morphology of CNWs with 20–30 nm diameter and 200–250 nm in length. X‐ray powder diffraction analysis confirmed highly crystalline nature of CNWs with 92.81% crystallinity. Incorporation of CNWs enhanced the thermal and mechanical properties of films. Fourier transform infrared spectroscopy data showed physical interactions between polymer‐polymer and polymer‐drug. Films prepared with CNWs showed improved swelling behavior which resulted in sustained drug release from polymeric matrix. In vitro curcumin release data were fitted with two‐step release model; Step 1 as desorption from the outer surface of the film, and Step 2 as diffusion from within the film and subsequent desorption. The release kinetics confirmed biphasic release profile with different release rates along with diffusion controlled curcumin release. Prepared films showed high biocompatibility with excellent antibacterial activities. Overall, the performed studies confirmed CS–PVP–CNWs based release system can as a potential candidate for wound dressing applications with sustained drug release. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2391–2404, 2017.
Serum free light chain quantitative assays: Dilemma of a biomarker
Authors: Cigliana Giovanni , Gulli Francesca , Napodano Cecilia , Pocino Krizia , De Santis Elena , Colacicco Luigi , Cordone Iole , Conti Laura , Basile Umberto
Published: April 2017

Background

Serum free light chains detection assays are consistently meeting greater interest for the diagnosis and monitoring of monoclonal gammopathies and plasma cell dyscrasias. Nowadays, there are neither standardized methods nor reference material for the determination of free light chains; for this reason, it is important to compare two different assays used in clinical laboratory.

Methods

We evaluated 300 serum samples from patients with B‐cell disorders and compared the analytical performances of both assay. Each test was assayed on both testing platforms (Siemens Dade Behring BN II Nephelometer and SPAPLUS by The Binding Site). κ/λ ratios were determined and compared. Results were analyzed by Passing‐Bablok and Bland‐Altman plots to evaluate comparability of the two techniques and to determine bias.

Results

The reproducibility of both assays is acceptable, reaching minimum and desirable analytical goals derived from biological variability. However, values are not interchangeable between systems. This study shows that the two systems do not allow results to be transferred from one method to the other even if they display good agreement.

Conclusion

Our study highlights the importance of elaborating an international standard for free light chains quantification in order to offer homogeneous results as well as guarantee harmonization of values among laboratories. Moreover, the assays should be validated in specific patient groups to determine that they are clinically fit for purpose.