bluuebunny/crossref_metadata_2025 huggingface dataset:
Organic Ring Oscillators with Sub‐200 ns Stage Delay Based on a Solution‐Processed p‐type Semiconductor Blend
Authors: Watson Colin P. , Brown Beverley A. , Carter Julian , Morgan John , Taylor D. Martin
Published: January 2016

High‐frequency ring oscillators with sub‐microsecond stage delay fabricated from spin‐coated films of a specially formulated small‐molecule/host‐polymer blend are reported. Contacts and interconnects are patterned by photolithography with plasma etching used for creating vias and removing excess material to reduce parasitic effects. The characteristics of transistors with 4.6 μm channel length scale linearly with channel width over the range 60–2160 μm. Model device parameters extracted using Silvaco's Universal Organic Thin Film Transistor (UOTFT) Model yield values of hole mobility increasing from 1.9 to 2.6 cm2 Vs−1 as gate voltage increased. Simulated and fabricated Vgs = 0 inverters predict that the technology is capable of fabricating 5‐stage ring oscillators operating above 100 kHz. Initial designs operated mainly at frequencies in the range 250–300 kHz, due to smaller parasitic gate overlap capacitances and higher supply voltages than assumed in the simulations. A design incorporating graded inverter sizes operates at frequencies above 400 kHz with the best reaching 529 kHz. The corresponding stage delay of 189 ns is the shortest reported to date for a solution‐processed p‐type semiconductor and compares favorably with similar circuits based on evaporated small molecules. Significant further improvements are identified which could lead to the fabrication of digital circuits that operate at much higher bit rates than previously reported.
Realization and control of multiple temperature zones in liquid‐containing gas–solid fluidized bed reactor
Authors: Zhou Yefeng , Shi Qiang , Huang Zhengliang , Liao Zuwei , Wang Jingdai , Yang Yongrong
Published: January 2016

Fluidized bed reactors (FBRs) have been developed to establish multiple temperature zones for various industrial processes. To overcome the common weakness, this work proposed to spray liquid into bottom and upper zones, respectively, to realize multiple temperature zones FBR (MTZFBR). Temperature, pressure, and acoustic emission techniques were applied to fully characterize liquid interaction and hydrodynamics. Compared with the bottom liquid‐spraying approach, the upper liquid‐spraying approach showed higher temperature difference (ΔT) and better fluidization stability, thus was selected for further control studies. Effects of liquid flow rate, static bed height, and inlet gas temperature on MTZFBR were studied systematically. The results showed that increasing liquid evaporation behavior or decreasing liquid bridge behavior enhance ΔT and fluidization stability and vice versa. G–L–S fluidization pattern depended mostly on the liquid behaviors and fluidization stability, and thus the stabilized MTZFBR could be regarded as a coexisted mode of two distinctive G–L–S fluidization patterns. © 2016 American Institute of Chemical EngineersAIChE J, 62: 1454–1466, 2016
Teflon AF2400/Ultem composite hollow fiber membranes for alcohol dehydration by high‐temperature vapor permeation
Authors: Hua Dan , Chung Tai‐Shung , Shi Gui Min , Fang Chao
Published: January 2016

High‐temperature vapor permeation has a stringent requirement of membrane stability under harsh feed environments. This work reports the design of Teflon AF2400/Ultem composite hollow fiber (HF) membranes for alcohol dehydration via vapor permeation. Fabrication parameters such as Teflon concentration and coating time were systematically investigated. Interestingly, the fabricated composite HF membranes possess an unusual surface with honeycomb‐like microstructure patterns. Owing to the Teflon protective layer, the newly developed composite HF shows a promising and stable separation performance with a flux of 4265 gm−2 h−1 and a separation factor of 383 for 95% isopropanol dehydration at 125°C. The composite HF also performs well under extreme vapor feed compositions from 87 to 99 wt % isopropanol. In addition, it exhibits impressive separation performance for the dehydration of ethanol and n‐butanol. This work may provide useful insights of designing thermal‐stable and high‐performance composite polymeric membranes for vapor permeation. © 2016 American Institute of Chemical Engineers AIChE J, 62: 1747–1757, 2016
(nBuCp)2ZrCl2‐catalyzed ethylene‐4M1P copolymerization: Copolymer backbone structure, melt behavior, and crystallization
Authors: Atiqullah Muhammad , Adamu Sagir , Malaibari Zuhair O. , Al‐Harthi Mamdouh A. , Emwas Abdul‐Hamid M.
Published: January 2016

The judicious design of methylaluminoxane (MAO) anions expands the scope for developing industrial metallocene catalysts. Therefore, the effects of MAO anion design on the backbone structure, melt behavior, and crystallization of ethylene−4‐methyl‐1‐pentene (E−4M1P) copolymer were investigated. Ethylene was homopolymerized, as well as copolymerized with 4M1P, using (1) MAO anion A (unsupported [MAOCl2]−) premixed with dehydroxylated silica, (nBuCp)2ZrCl2, and Me2SiCl2; and (2) MAO anion B (Si−O−Me2Si−[MAOCl2]−) supported with (nBuCp)2ZrCl2on Me2SiCl2‐functionalized silica. Unsupported Me2SiCl2, opposite to the supported analogue, acted as a co‐chain transfer agent with 4M1P. The modeling of polyethylene melting and crystallization kinetics, including critical crystallite stability, produced insightful results. This study especially illustrates how branched polyethylene can be prepared from ethylene alone using particularly one metallocene‐MAO ion pair, and how a compound, that functionalizes silica as well as terminates the chain, can synthesize ethylene−α‐olefin copolymers with novel structures. Hence, it unfolds prospective future research niches in polyethyne systhesis. © 2016 American Institute of Chemical EngineersAIChE J, 62: 1688–1706, 2016
Predicting effective conductivities based on geometric microstructure characteristics
Authors: Stenzel Ole , Pecho Omar , Holzer Lorenz , Neumann Matthias , Schmidt Volker
Published: January 2016

Empirical relationships between effective conductivities in porous and composite materials and their geometric characteristics such as volume fraction
, tortuosity τ and constrictivity β are established. For this purpose, 43 virtually generated 3D microstructures with varying geometric characteristics are considered. Effective conductivities
are determined by numerical transport simulations. Using error‐minimization the following relationships have been established:
and
(simplified formula) with intrinsic conductivity σ0, geodesic tortuosity
and relative prediction errors of 19% and 18%, respectively. We critically analyze the methodologies used to determine tortuosity and constrictivity. Comparing geometric tortuosity and geodesic tortuosity, our results indicate that geometric tortuosity has a tendency to overestimate the windedness of transport paths. Analyzing various definitions of constrictivity, we find that the established definition describes the effect of bottlenecks well. In summary, the established relationships are important for a purposeful optimization of materials with specific transport properties, such as porous electrodes in fuel cells and batteries. © 2016 American Institute of Chemical Engineers AIChE J, 62: 1834–1843, 2016
A numerical study exploring the effect of particle properties on the fluidization of adhesive particles
Authors: Wilson Robert , Dini Daniele , van Wachem Berend
Published: January 2016

The effects of varying the elastic modulus, coefficient of restitution, and coefficient of friction of adhesive particles on fluidized bed dynamics have been investigated via numerical simulations. It is found that lower values of the elastic modulus and coefficient of restitution lead to a greater degree of particle clustering, and the formation of smaller bubbles. Coordination numbers are found to initially increase, and then fall, with increasing coefficient of friction, while bubble velocities follow the opposite trend. It is concluded that artificially reducing the elastic modulus of adhesive particles has a significant impact on the fluidization behavior. The change in dynamics of the fluidized bed due to varying the coefficient of friction is more complex: particle clustering increases up to a point, beyond which clusters become increasingly rigid. © 2016 American Institute of Chemical Engineers AIChE J, 62: 1467–1477, 2016
Kinetic modeling of 1,2‐dichloropropane (PDC) free‐radical chlorination
Authors: Wang Hangyao , Tirtowidjojo Max , Zarth Christina , Laitar David
Published: January 2016

Recent government mandates have lowered the permissible global warming potential (GWP) for refrigerants in mobile air conditioning substantially below that of the hydrofluorocarbon products that are used currently. Potential replacements, hydrofluoro‐olefins (HFO), have a reduced impact on the ozone layer and lower GWP. Many desirable HFO compounds, such as HFO‐1234yf, can be produced utilizing chlorocarbons as feedstocks such as the preferred 1,1,2,3‐tetrachloropropene (TCPE). TCPE can be produced by several routes; however, producing TCPE from 1,2‐dichloropropane (PDC) is potentially more desirable environmentally and economically since PDC is a byproduct of propylene oxide and allyl chloride production. One process option is to convert PDC to pentachloropropane (PCP) intermediates by chlorination, followed by dehydrochlorination of the PCPs to produce TCPE. In this work, we show that PCPs can be produced through the chlorination of PDC in a free‐radical liquid phase reaction and have developed a kinetic model for PDC chlorination based on the relevant free radical elementary reactions. Thermodynamic properties including standard heats of formation, standard entropies of formation, and heat capacities for the radical and non‐radical species were estimated by using ab initio and COSMOtherm calculations and validated against available experimental data. The reaction equilibrium constants were determined from the Gibb's free energies of the reactants and products. Phase equilibria were calculated by means of a consistent set of thermodynamic properties of the species. In addition, physical properties such as the vapor pressure of pure components involved in the reaction network were also estimated. Ab initio transition state calculations were employed to estimate the rate parameters including pre‐exponential factors and activation energies for the relevant reactions. The activation energies of some key reactions were then adjusted to match experimental data. The resulting kinetic model provided a basis for process yield optimization and scale up. © 2016 American Institute of Chemical Engineers AIChE J, 62: 1174–1191, 2016
Spleen enlargement is a risk factor for thrombosis in essential thrombocythemia: Evaluation on 1,297 patients
Authors: Andriani Alessandro , Latagliata Roberto , Anaclerico Barbara , Spadea Antonio , Rago Angela , Di Veroli Ambra , Spirito Francesca , Porrini Raffaele , De Muro Marianna , Crescenzi Leonetti Sabrina , Villivà Nicoletta , De Gregoris Cinzia , Montefusco Enrico , Polverelli Nicola , Santoro Cristina , Breccia Massimo , Cimino Giuseppe , Majolino Ignazio , Mazzucconi Maria Gabriella , Vianelli Nicola , Alimena Giuliana , Montanaro Marco , Palandri Francesca
Published: January 2016

Spleen enlargement, present in 10–20% of Essential Thrombocythemia (ET) patients at diagnosis, is a feature clinically easy to assess, confirmable by echography with a very low chance of misinterpretation. Nonetheless, the clinical and prognostic role of splenomegaly has been seldom evaluated. From 1979 to 2013, 1297 ET patients retrospectively collected in the database of the Lazio Cooperative Group and Bologna University Hospital were evaluable for spleen enlargement at diagnosis and included in the analysis. On the whole, spleen was enlarged in 172/1297 (13.0%) patients; in most cases (94.8%) splenomegaly was mild (≤5 cm). Patients with splenomegaly were younger, predominantly male, presented higher platelet count and JAK2V617F allele burden and had a lower incidence of concomitant cardiovascular risk factors. At least one thrombotic event during follow‐up occurred in 97/1,125 (8.6%) patients without spleen enlargement compared to 27/172 (15.7%) patients with spleen enlargement (P = 0.003). Despite comparable use of cytoreductive/antiplatelet therapies in the two groups, the cumulative risk of thrombosis at 5 years was significantly higher in patients with baseline splenomegaly (9.8% versus 4.4% in patients without splenomegaly, P = 0.012). In multivariate analysis exploring risk factors for thrombosis, splenomegaly retained its negative prognostic role, together with previous thrombosis, leucocyte count and male gender. Baseline splenomegaly seems to be an independent additional risk factor for thrombosis in nonstrictly WHO‐defined ET patients. This data could be useful in the real‐life clinical management of these patients. Am. J. Hematol. 91:318–321, 2016. © 2016 Wiley Periodicals, Inc.
Bone marrow infiltration by multiple myeloma causes anemia by reversible disruption of erythropoiesis
Authors: Bouchnita Anass , Eymard Nathalie , Moyo Tamara K. , Koury Mark J. , Volpert Vitaly
Published: January 2016

Multiple myeloma (MM) infiltrates bone marrow and causes anemia by disrupting erythropoiesis, but the effects of marrow infiltration on anemia are difficult to quantify. Marrow biopsies of newly diagnosed MM patients were analyzed before and after four 28‐day cycles of nonerythrotoxic remission induction chemotherapy. Complete blood cell counts and serum paraprotein concentrations were measured at diagnosis and before each chemotherapy cycle. At diagnosis, marrow area infiltrated by myeloma correlated negatively with hemoglobin, erythrocytes, and marrow erythroid cells. After successful chemotherapy, patients with less than 30% myeloma infiltration at diagnosis had no change in these parameters, whereas patients with more than 30% myeloma infiltration at diagnosis increased all three parameters. Clinical data were used to develop mathematical models of the effects of myeloma infiltration on the marrow niches of terminal erythropoiesis, the erythroblastic islands (EBIs). A hybrid discrete‐continuous model of erythropoiesis based on EBI structure/function was extended to sections of marrow containing multiple EBIs. In the model, myeloma cells can kill erythroid cells by physically destroying EBIs and by producing proapoptotic cytokines. Following chemotherapy, changes in serum paraproteins as measures of myeloma cells and changes in erythrocyte numbers as measures of marrow erythroid cells allowed modeling of myeloma cell death and erythroid cell recovery, respectively. Simulations of marrow infiltration by myeloma and treatment with nonerythrotoxic chemotherapy demonstrate that myeloma‐mediated destruction and subsequent reestablishment of EBIs and expansion of erythroid cell populations in EBIs following chemotherapy provide explanations for anemia development and its therapy‐mediated recovery in MM patients. Am. J. Hematol. 91:371–378, 2016. © 2016 Wiley Periodicals, Inc.
Novel missense mutations in a conserved loop between ERCC6 (CSB) helicase motifs V and VI: Insights into Cockayne syndrome
Authors: Wilson Brian T. , Lochan Anneline , Stark Zornitza , Sutton Ruth E.
Published: January 2016

Cockayne syndrome is caused by biallelic ERCC8 (CSA) or ERCC6 (CSB) mutations and is characterized by growth restriction, microcephaly, developmental delay, and premature pathological aging. Typically affected patients also have dermal photosensitivity. Although Cockayne syndrome is considered a DNA repair disorder, patients with UV‐sensitive syndrome, with ERCC8 (CSA) or ERCC6 (CSB) mutations have indistinguishable DNA repair defects, but none of the extradermal features of Cockayne syndrome. We report novel missense mutations affecting a conserved loop in the ERCC6 (CSB) protein, associated with the Cockayne syndrome phenotype. Indeed, the amino acid sequence of this loop is more highly conserved than the adjacent helicase motifs V and VI, suggesting that this is a crucial structural component of the SWI/SNF family of proteins, to which ERCC6 (CSB) belongs. These comprise two RecA‐like domains, separated by an interdomain linker, which interact through helicase motif VI. As the observed mutations are likely to act through destabilizing the tertiary protein structure, this prompted us to re‐evaluate ERCC6 (CSB) mutation data in relation to the structure of SWI/SNF proteins. Our analysis suggests that antimorphic mutations cause Cockayne syndrome and that biallelic interdomain linker deletions produce more severe phenotypes. Based on our observations, we propose that further investigation of the pathogenic mechanisms underlying Cockayne syndrome should focus on the effect of antimorphic rather than null ERCC6 (CSB) mutations. © 2016 Wiley Periodicals, Inc.
Novel copy number variants and major limb reduction malformation: Report of three cases
Authors: Shamseldin Hanan E. , Anazi Shams , Wakil Salma M. , Faqeih Eissa , El Khashab Heba Y. , Salih Mustafa A. , Al‐Qattan Mohammad M. , Hashem Mais , Alsedairy Haifa , Alkuraya Fowzan S.
Published: January 2016

Limb reduction malformations are highly heterogeneous in their clinical presentation and so, predicting the underlying mutation on a clinical basis can be challenging. Molecular karyotyping is a powerful genomic tool that has quickly become the mainstay for the study of children with malformation syndromes. We describe three patients with major limb reduction anomalies in whom pathogenic copy number variants were identified on molecular karyotyping. These include a patient with hypoplastic phalanges and absent hallux bilaterally with de novo deletion of 11.9 Mb on 7p21.1–22.1 spanning 63 genes including RAC1, another patient with severe Holt–Oram syndrome and a large de novo deletion 2.2 Mb on 12q24.13–24.21 spanning 20 genes including TBX3 and TBX5, and a third patient with acheiropodia who had a nullizygous deletion of 102 kb on 7q36.3 spanning LMBR1. We discuss the potential of these novel genomic rearrangements to improve our understanding of limb development in humans. © 2016 Wiley Periodicals, Inc.
Interstitial 6q25 microdeletion syndrome: ARID1B is the key gene
Authors: Ronzoni Luisa , Tagliaferri Francesco , Tucci Arianna , Baccarin Marco , Esposito Susanna , Milani Donatella
Published: January 2016

Interstitial deletions of the long arm of chromosome 6 are rare. Clinically, these deletions are considered to be part of a unique microdeletion syndrome associated with intellectual disability and speech impairment, typical dysmorphic features, structural anomalies of the brain, microcephaly, and non‐specific multiple organ anomalies. The critical region for the interstitial 6q microdeletion phenotype was mapped to 6q24–6q25, particularly the 6q25.3 region containing the genes ARID1B and ZDHHC14. It has been hypothesized that haploinsufficiency of these genes impairs normal development of the brain and is responsible for the phenotype. This case report describes a girl presenting with typical features of 6q microdeletion syndrome, including global developmental delay, speech impairment, distinct dysmorphic features, dysgenesis of the corpus callosum, common limb anomalies, and hearing loss. Chromosome analysis by array‐CGH revealed a small interstitial 6q deletion spanning approximately 1.1 Mb of DNA and containing only one coding gene, ARID1B. We suggest that ARID1B is the key gene behind 6q microdeletion syndrome, and we discuss its possible role in the phenotypic manifestations. © 2016 Wiley Periodicals, Inc.
Intermolecular C−N Cross‐Coupling Reactions Catalyzed by Tetra‐n‐butylammonium Iodide: Synthesis of Allylic N‐Heterocycles
Authors: Lv Yunhe , Sun Kai , Wang Tingting , Wu Yingtao , Li Gang , Pu Weiya , Mao Shukuan
Published: January 2016

Tetra‐n‐butylammonium iodide (nBu4NI)‐catalyzed C−N bond formation for the synthesis of allylic N‐heterocycles was achieved under metal‐free conditions. The reaction is applicable to the coupling of a range of allylic hydrocarbons with biologically active purines, benzimidazoles, benzotriazoles, and saccharin. The reaction mechanism was primarily investigated and a radical process was proposed.
Postnatal craniofacial ontogeny in neandertals and modern humans
Authors: Williams Frank L'Engle , Cofran Zachary
Published: January 2016

Objectives

Neandertals and humans are closely related but differ noticeably in adult morphology. Previous work has been equivocal as to the contribution of postnatal growth and development to these differences. Due to disparate preservation, most analyses focus on specific anatomies, reconstructed fossils, or limited sample sizes. The objective of this research is to highlight the importance of postnatal growth in expressing Neandertal‐human distinctions in the craniofacial skeleton, using a large and unreconstructed Neandertal sample.

Materials/Methods

A resampling approach is utilized to compare relative size change in 20 craniofacial dimensions between Neandertals (n = 42) and humans (n = 262). The large number of immature Neandertal samples within and between dental stages provides the necessary variation to test for growth differences. Nested resampling using human‐human comparisons assesses the likelihood of observing human‐Neandertal growth differences under the null hypothesis of similar ontogenetic variation.

Results

Humans and Neandertals undergo comparable levels of overall size change. However, we identify growth differences for a number of traits, helping explain some of the unique features of this fossil taxon. Nested resampling shows it is unlikely that a Neandertal‐like maturation would be observed in a random ontogenetic sample of humans.

Discussion

Growth during adolescence appears to be fundamental in the expression of some Neandertal anatomies. Neandertal upper facial and nasal breadths appear to have expanded rapidly after puberty to account for differences between preadolescents and adults, and Neandertals and humans. Mandibular growth differences may relate to anterior tooth use to process foods and paramastication during Neandertal maturation. Am J Phys Anthropol 159:394–409, 2016. © 2016 Wiley Periodicals, Inc.
Technical note: Performance of semi and fully automated approaches for registration of 3D surface coordinates in geometric morphometric studies
Authors: Gonzalez Paula N. , Barbeito‐Andrés Jimena , D'Addona Lucas A. , Bernal Valeria , Perez S. Ivan
Published: January 2016

Objectives

One of the biggest challenges in the study of complex morphologies is to adequately describe shape variation. Here, we assess how the random sampling of surface points automatically obtained performs, when compared with observer‐guided sampling procedures, and also evaluate the effect of sliding surface points by bending energy and minimum Procrustes distance.

Material and methods

Three datasets comprising structures with disparate levels of complexity and intrasample variation are as follows: mouse molars, mouse brains, and primate endocasts. Different configurations of 3D coordinates on curves and surfaces were digitized from MRI images and CT scans using semi and fully automated procedures. Shape variables were obtained by Generalized Procrustes Superpositions before and after sliding the pseudolandmarks. Multivariate analyses were used to summarize and compare shape variation.

Results

For the primate endocast, the semiautomated and automated strategies yield similar ordinations of specimens. Conversely, the semiautomated strategy better discriminates molar shapes between mouse groups. Shape differences among specimens are not adequately represented by the PCs calculated with surface pseudolandmarks. This is improved when the points are converted into semilandmarks by a sliding criterion.

Discussion

Surface semilandmarks automatically obtained from 3D models are promising although they should be used with some caution in complex structures. This approach can be taken as complementary of semiautomated procedures which perform better for assessing shape variation in localized traits previously selected while automated procedures are suitable in studies aimed at comparing overall variation in shape and when there is no previous information about highly variable anatomical regions. Am J Phys Anthropol 160:169–178, 2016. © 2016 Wiley Periodicals, Inc.
Separate Einstein‐Eddington spaces and the cosmological constant
Authors: Azri Hemza
Published: January 2016

Based on Eddington affine variational principle on a locally product manifold, we derive the separate Einstein space described by its Ricci tensor. The derived field equations split into two field equations of motion that describe two maximally symmetric spaces with two cosmological constants. We argue that the invariance of the bi‐field equations under projections on the separate spaces, may render one of the cosmological constants to zero. We also formulate the model in the presence of a scalar field. The resulted separate Einstein‐Eddington spaces maybe considered as two states that describe the universe before and after inflation. A possibly interesting affine action for a general perfect fluid is also proposed. It turns out that the condition which leads to zero cosmological constant in the vacuum case, eliminates here the effects of the gravitational mass density of the perfect fluid, and the dynamic of the universe in its final state is governed by only the inertial mass density of the fluid.

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Elektrisch leitfähige poröse Metall‐organische Gerüstverbindungen
Authors: Sun Lei , Campbell Michael G. , Dincă Mircea
Published: January 2016

Aufgrund ihrer strukturellen, chemischen und funktionellen Vielfalt werden Metall‐organische Gerüstverbindungen (MOFs) seit etwa zwei Jahrzehnten für energierelevante Anwendungen erforscht. Bis vor kurzem mangelte es dabei aber an Anwendungen, für die ein guter Ladungstransport zusammen mit Porosität und einer großen Oberfläche erforderlich ist. Die meisten MOFs sind elektrische Isolatoren, und erst unlängst wurde für einige Materialien dieser Klasse ausgezeichnete elektrische Leitfähigkeit und hohe Ladungsmobilität gefunden. In diesem Aufsatz geben wir eine Übersicht über synthetische und elektronische Designstrategien für Gerüste mit permanenter Porosität und Ladungstransport über große Distanzen. Ferner diskutieren wir wegweisende Experimente zum elektrischen Ladungstransport und ausgewählte Anwendungen für diese spezielle Unterklasse von MOFs.
Hypercrosslinked Additives for Ageless Gas‐Separation Membranes
Authors: Lau Cher Hon , Mulet Xavier , Konstas Kristina , Doherty Cara M. , Sani Marc‐Antoine , Separovic Frances , Hill Matthew R. , Wood Colin D.
Published: January 2016

The loss of internal pores, a process known as physical aging, inhibits the long‐term use of the most promising gas‐separation polymers. Previously we reported that a porous aromatic framework (PAF‐1) could form a remarkable nanocomposite with gas‐separation polymers to stop aging. However, PAF‐1 synthesis is very onerous both from a reagent and reaction‐condition perspective, making it difficult to scale‐up. We now reveal a highly dispersible and scalable additive based on α,α′‐dichloro‐p‐xylene (p‐DCX), that inhibits aging more effectively, and crucially almost doubles gas‐transport selectivity. These synergistic effects are related to the intimately mixed nanocomposite that is formed though the high dispersibility of p‐DCX in the gas‐separation polymer. This reduces particle‐size effects and the internal free volume is almost unchanged over time. This study shows this inexpensive and scalable polymer additive delivers exceptional gas‐transport performance and selectivity.
Mesoporous Manganese Oxide Catalyzed Aerobic Oxidative Coupling of Anilines To Aromatic Azo Compounds
Authors: Dutta Biswanath , Biswas Sourav , Sharma Vinit , Savage Nancy Ortins , Alpay S. Pamir , Suib Steven L.
Published: January 2016

Herein we introduce an environmentally friendly approach to the synthesis of symmetrical and asymmetrical aromatic azo compounds by using air as the sole oxidant under mild reaction conditions in the presence of cost‐effective and reusable mesoporous manganese oxide materials.
iBodies: Modular Synthetic Antibody Mimetics Based on Hydrophilic Polymers Decorated with Functional Moieties
Authors: Šácha Pavel , Knedlík Tomáš , Schimer Jiří , Tykvart Jan , Parolek Jan , Navrátil Václav , Dvořáková Petra , Sedlák František , Ulbrich Karel , Strohalm Jiří , Majer Pavel , Šubr Vladimír , Konvalinka Jan
Published: January 2016

Antibodies are indispensable tools for biomedicine and anticancer therapy. Nevertheless, their use is compromised by high production costs, limited stability, and difficulty of chemical modification. The design and preparation of synthetic polymer conjugates capable of replacing antibodies in biomedical applications such as ELISA, flow cytometry, immunocytochemistry, and immunoprecipitation is reported. The conjugates, named “iBodies”, consist of an HPMA copolymer decorated with low‐molecular‐weight compounds that function as targeting ligands, affinity anchors, and imaging probes. We prepared specific conjugates targeting several proteins with known ligands and used these iBodies for enzyme inhibition, protein isolation, immobilization, quantification, and live‐cell imaging. Our data indicate that this highly modular and versatile polymer system can be used to produce inexpensive and stable antibody substitutes directed toward virtually any protein of interest with a known ligand.
Dimerization of Organic Dyes on Luminescent Gold Nanoparticles for Ratiometric pH Sensing
Authors: Sun Shasha , Ning Xuhui , Zhang Greg , Wang Yen‐Chung , Peng Chuanqi , Zheng Jie
Published: January 2016

Synergistic effects arising from the conjugation of organic dyes onto non‐luminescent metal nanoparticles (NPs) have greatly broadened their applications in both imaging and sensing. Herein, we report that conjugation of a well‐known pH‐insensitive dye, tetramethyl‐rhodamine (TAMRA), to pH‐insensitive luminescent gold nanoparticles (AuNPs) can lead to an ultrasmall nanoindicator that can fluorescently report local pH in a ratiometric way. Such synergy originated from the dimerization of TAMRA on AuNPs, of which geometry was very sensitive to surface charges of the AuNPs and can be reversely modulated through protonation of surrounding glutathione ligands. Not limited to pH‐insensitive dyes, this pH‐dependent dimerization can also enhance the pH sensitivity of fluorescein, a well‐known pH‐sensitive dye, within a larger pH range, opening up a new pathway to design ultrasmall fluorescent ratiometric nanoindicators with tunable wavelengths and pH response ranges.
Expedient Synthesis of (+)‐Lycopalhine A
Authors: Williams Benjamin M. , Trauner Dirk
Published: January 2016

Two amino acids play a key role in the first total synthesis of lycopalhine A. l‐glutamic acid serves as a convenient chiral starting material for the 13‐step synthesis, and l‐proline promotes an unusual 5‐endo‐trig Mannich cyclization that generates the central pyrrolidine ring of the Lycopodium alkaloid. The bicyclo[3.3.0]octanol moiety of the molecule is formed through an intramolecular aldol addition that may occur spontaneously in nature.
Recognition and Sensing of Creatinine
Authors: Guinovart Tomàs , Hernández‐Alonso Daniel , Adriaenssens Louis , Blondeau Pascal , Martínez‐Belmonte Marta , Rius F. Xavier , Andrade Francisco J. , Ballester Pablo
Published: January 2016

Current methods for creatinine quantification suffer from significant drawbacks when aiming to combine accuracy, simplicity, and affordability. Here, an unprecedented synthetic receptor, an aryl‐substituted calix[4]pyrrole with a monophosphonate bridge, is reported that displays remarkable affinity for creatinine and the creatininium cation. The receptor works by including the guest in its deep and polar aromatic cavity and establishing directional interactions in three dimensions. When incorporated into a suitable polymeric membrane, this molecule acts as an ionophore. A highly sensitive and selective potentiometric sensor suitable for the determination of creatinine levels in biological fluids, such as urine or plasma, in an accurate, fast, simple, and cost‐effective way has thus been developed.
A Potent Glucose–Platinum Conjugate Exploits Glucose Transporters and Preferentially Accumulates in Cancer Cells
Authors: Patra Malay , Johnstone Timothy C. , Suntharalingam Kogularamanan , Lippard Stephen J.
Published: January 2016

Three rationally designed glucose–platinum conjugates (Glc–Pts) were synthesized and their biological activities evaluated. The Glc–Pts, 1–3, exhibit high levels of cytotoxicity toward a panel of cancer cells. The subcellular target and cellular uptake mechanism of the Glc–Pts were elucidated. For uptake into cells, Glc–Pt 1 exploits both glucose and organic cation transporters, both widely overexpressed in cancer. Compound 1 preferentially accumulates in and annihilates cancer, compared to normal epithelial, cells in vitro.
Expanding the Landscape of Diterpene Structural Diversity through Stereochemically Controlled Combinatorial Biosynthesis
Authors: Andersen‐Ranberg Johan , Kongstad Kenneth Thermann , Nielsen Morten Thrane , Jensen Niels Bjerg , Pateraki Irini , Bach Søren Spanner , Hamberger Britta , Zerbe Philipp , Staerk Dan , Bohlmann Jörg , Møller Birger Lindberg , Hamberger Björn
Published: January 2016

Plant‐derived diterpenoids serve as important pharmaceuticals, food additives, and fragrances, yet their low natural abundance and high structural complexity limits their broader industrial utilization. By mimicking the modularity of diterpene biosynthesis in plants, we constructed 51 functional combinations of class I and II diterpene synthases, 41 of which are “new‐to‐nature”. Stereoselective biosynthesis of over 50 diterpene skeletons was demonstrated, including natural variants and novel enantiomeric or diastereomeric counterparts. Scalable biotechnological production for four industrially relevant targets was accomplished in engineered strains of Saccharomyces cerevisiae.
Assembly of an Axially Chiral Dynamic Redox System with a Perfluorobiphenyl Skeleton into Dumbbell‐ or Tripod‐type Electron Donors
Authors: Tamaoki Hitomi , Katoono Ryo , Fujiwara Kenshu , Suzuki Takanori
Published: January 2016

The incorporation of F atoms endows a diethenylbiphenyl‐based electron donor with configurational stability and SNAr reactivity. The former enables the dynamic redox pair of (Rax)‐1/(Rax,R,R)‐12+ to exhibit drastic UV/Vis and CD spectral changes upon electrolysis, whereas the latter makes it possible for (Rax)‐1 to serve as a useful chiral synthon for the production of larger assemblies [(Rax,Rax)‐2 d,p,m and (Rax,Rax,Rax)‐3] containing two or three dyrex units. These dyads and triad also exhibit a clean electrochiroptical response with isosbestic points owing to one‐wave multi‐electron transfer.
Metal‐Free Synthesis of Fluorinated Indoles Enabled by Oxidative Dearomatization
Authors: Vitaku Edon , Smith David T. , Njardarson Jon T.
Published: January 2016

Nitrogen heterocycles are found in a majority of approved small‐molecule pharmaceuticals, and the number of approved fluorinated drugs is increasing each decade. Therefore, new approaches for accessing fluorinated nitrogen heterocycles are of great significance. A novel, scalable, and metal‐free method for accessing a wide range of fluorinated indoles is described. This oxidative‐dearomatization‐enabled approach assembles 2‐trifluoromethyl NH‐indole products from simple commercially available anilines with hexafluoroacetylacetone in the presence of an organic oxidant. The nature of the aniline N‐capping group is critical for the success of this new reaction. Furthermore, the indole products contain a 3‐trifluoroacetyl group, which can be exploited to access a plethora of useful functional groups.
Electrically Conductive Porous Metal–Organic Frameworks
Authors: Sun Lei , Campbell Michael G. , Dincă Mircea
Published: January 2016

Owing to their outstanding structural, chemical, and functional diversity, metal–organic frameworks (MOFs) have attracted considerable attention over the last two decades in a variety of energy‐related applications. Notably missing among these, until recently, were applications that required good charge transport coexisting with porosity and high surface area. Although most MOFs are electrical insulators, several materials in this class have recently demonstrated excellent electrical conductivity and high charge mobility. Herein we review the synthetic and electronic design strategies that have been employed thus far for producing frameworks with permanent porosity and long‐range charge transport properties. In addition, key experiments that have been employed to demonstrate electrical transport, as well as selected applications for this subclass of MOFs, will be discussed.
Structure‐Based Development of an Affinity Probe for Sirtuin 2
Authors: Schiedel Matthias , Rumpf Tobias , Karaman Berin , Lehotzky Attila , Gerhardt Stefan , Ovádi Judit , Sippl Wolfgang , Einsle Oliver , Jung Manfred
Published: January 2016

Sirtuins are NAD+‐dependent protein deacylases that cleave off acetyl groups, as well as other acyl groups, from the ɛ‐amino group of lysines in histones and other substrate proteins. Dysregulation of human Sirt2 activity has been associated with the pathogenesis of cancer, inflammation, and neurodegeneration, thus making Sirt2 a promising target for pharmaceutical intervention. Here, based on a crystal structure of Sirt2 in complex with an optimized sirtuin rearranging ligand (SirReal) that shows improved potency, water solubility, and cellular efficacy, we present the development of the first Sirt2‐selective affinity probe. A slow dissociation of the probe/enzyme complex offers new applications for SirReals, such as biophysical characterization, fragment‐based screening, and affinity pull‐down assays. This possibility makes the SirReal probe an important tool for studying sirtuin biology.
Numerical and experimental investigations on the physical characteristics of supersonic steam jet induced hydrodynamic instabilities
Authors: Khan Afrasyab , Sanaullah Khairuddin , Takriff M. Sobri , Zen Hushairi , Rigit Andrew Ragai Henry , Shah Ajmal , Chughtai Imran Rafiq
Published: January 2016

Hydrodynamic instabilities play a silent lethal role for the systems involving steam as one of its working fluid. They reduce the fatigue life of the pipes by exerting stresses at their walls. These instabilities created at the interface between steam and water and propagated towards the walls of the confinement. In the current research, three physical characteristics of these hydrodynamic instabilities have been discussed using Computational Fluid Dynamic (CFD) as well as experimental approaches. These characteristics include their spatial prevalence on the length scale, amplitude, and the number of their occurrences. All of these characteristics have been predicted at specific hydrodynamic conditions in terms of temperature fluctuations. It has been observed that these characteristics are exhibited by the hydrodynamic instabilities in a random and non‐deterministic manner. © 2016 Curtin University of Technology and John Wiley & Sons, Ltd.
Investigation of the effects of perlite additive on some comfort and acoustical properties of polyester fabrics
Authors: Karaca Esra , Omeroglu Sunay , Akcam Okan
Published: January 2016

Natural perlite material was added for the first time into a polyester filament yarn structure. The water absorption and heat and sound insulation properties of the fabrics produced from textured and twisted polyester yarns containing 1.25% perlite additive were tested, and the results were compared with those obtained on the fabrics produced from reference polyester yarns. Although there are differences between the mechanical properties of the polyester yarns, the yarns including perlite remained within commercial usage limits. The thermal resistance values of polyester sateen fabrics obtained from perlite‐containing yarns were higher than those of the reference fabrics. The contribution of perlite led to a marked improvement, especially in the hydrophilicity and sound insulation of the polyester fabrics. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43128.
POEGMA‐b‐PAA comb‐like polymer dispersant for Al2 suspensions
Authors: Wang Anqi , Qiao Min , Xu Jian , Pan Yumei , Ran Qianping , Wu Shishan , Chen Qiang
Published: January 2016

POEGMA‐b‐PAA comb‐like polymer is synthesized through RAFT polymerization, and it is employed as an efficient dispersant for Al2O3 suspensions. The POEGMA‐b‐PAA polymer consists of PAA chains and POEGMA comb‐like chains. The former provide electrostatic attraction between Al2O3 particles and polymer, while the latter extend to solution and maintain the stability of suspension due to strong steric hindrance. The adsorption is proven and the rheology behaviors of Al2O3 suspensions are strongly improved. Different POEGMA‐b‐PAA polymers with different length of side chains have similar but not identical rheological properties. The polymer with the appropriate length of side chain provides the biggest improvement to rheological properties of Al2O3 suspensions, such as apparent viscosity and granularity. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43352.
Preparation of PTFE/graphene nanocomposites by compression moulding and free sintering: A guideline
Authors: van Rooyen Louis Johann , Bissett Hertzog , Khoathane Moshibudi Caroline , Karger‐Kocsis Jozsef
Published: January 2016

This work was aimed at preparing polytetrafluoroethylene (PTFE) nanocomposites filled with graphene nanoplatelets and investigating how the graphene nanoplatelets and the preparation techniques influenced the physical properties. Graphene was incorporated up to 4 vol % of the total PTFE system by dry and solvent assisted blending. The powder compaction was evaluated using the Kawakita/Ludde model to describe the compressibility of the powder blends. The nanocomposite billets were prepared using cold compression moulding by applying preform pressures between 12.7 and 140 MPa and the preform billets were sintered at 380°C using a specific sintering cycle. The changes in the physical dimensions, billet mass, density, and void content of the billets, pre and post sintering, were analyzed with experimental design to evaluate the influence of the precompaction pressure and graphene loading. From the evaluation it was concluded that the ideal compaction pressure was at 12.7 MPa and the solvent assisted blending was superior to the mechanical blending method. Furthermore, the compression creep tests confirmed the ideal processing temperature and graphene loading range to improve the mechanical properties. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43369.
EXPRESSION PATTERNS OF THE GLYCOGEN PHOSPHORYLASE GENE RELATED TO LARVAL DIAPAUSE IN Ostrinia furnacalis
Authors: Guo Jianqing , Zhang Honggang , Edwards Martin , Wang Zhenying , Bai Shuxiong , He Kanglai
Published: January 2016

Glycogen phosphorylase (GP) acts in the first step in release of glucose from glycogen, a form of energy storage for most organisms. To investigate the characteristics and expression pattern of GP gene (Ofgp) in the Asian corn borer, Ostrinia furnacalis (Guenée), larvae, we cloned and analyzed tissue transcription of Ofgp. The results indicate that the open reading frame (ORF) is 2,526 bp, encoding 841 amino acid. The calculated three‐dimensional structure shows 33 α‐helices and 24 β‐sheets. Ofgp transcription levels varied significantly during the second to fifth instars under long‐day (28°C, 16:8 L:D photoperiod, and 70–80% relative humidity (RH)) and short‐day (24.5°C, 11:13 L:D photoperiod, and 70–80% RH) conditions, remained low during the prediapause phase, and then increased after about 36 d under short‐day photoperiod. In the larvae reared under long‐day condition, hemolymph ranked the highest in the transcript level of Ofgp. The highest transcription was recorded in the fat body and was lower in the other tissues in larvae reared under short‐day condition. We found that Ofgp transcription increased linearly from October 2012 to January 2013. The transcript level was negatively correlated with environmental temperature. We infer the higher Ofgp transcription may enhance the cold hardiness of the diapause larvae.
Increased Conformational Flexibility of HLA–B*27 Subtypes Associated With Ankylosing Spondylitis
Authors: Loll Bernhard , Fabian Heinz , Huser Hans , Hee Chee‐Seng , Ziegler Alexander , Uchanska‐Ziegler Barbara , Ziegler Andreas
Published: January 2016

Objective

Dissimilarities in antigen processing and presentation are known to contribute to the differential association of HLA–B*27 subtypes with the inflammatory rheumatic disease ankylosing spondylitis (AS). In support of this notion, previous x‐ray crystallographic data showed that peptides can be displayed by almost identical HLA–B*27 molecules in a subtype‐dependent manner, allowing cytotoxic T lymphocytes to distinguish between these subtypes. For example, a human self‐peptide derived from vasoactive intestinal peptide receptor type 1 (pVIPR; sequence RRKWRRWHL) is displayed in a single conformation by B*27:09 (which is not associated with AS), while B*27:05 (which is associated with AS) presents the peptide in a dual binding mode. In addition, differences in conformational flexibility between these subtypes might affect their stability or antigen presentation capability. This study was undertaken to investigate B*27:04 and B*27:06, another pair of minimally distinct HLA–B*27 subtypes, to assess whether dual peptide conformations or structural dynamics play a role in the initiation of AS.

Methods

Using x‐ray crystallography, we determined the structures of the pVIPR–B*27:04 and pVIPR–B*27:06 complexes and used isotope‐edited infrared (IR) spectroscopy to probe the dynamics of these HLA–B*27 subtypes.

Results

As opposed to B*27:05 and B*27:09, B*27:04 (which is associated with AS) displays pVIPR conventionally and B*27:06 (which is not associated with AS) presents the peptide in a dual conformation. Comparison of the 4 HLA–B*27 subtypes using IR spectroscopy revealed that B*27:04 and B*27:05 possess elevated molecular dynamics compared to the nonassociated subtypes B*27:06 and B*27:09.

Conclusion

Our results demonstrate that an increase in conformational flexibility characterizes the disease‐associated subtypes B*27:04 and B*27:05.