bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and evaluation of properties of poly(p‐phenylenevinylene) based 1,3,4‐oxadiazole systems for optoelectronics and nonlinear optical applications
Authors: Kaippamangalath Nimisha , Gopalakrishnapanicker Unnikrishnan 
Published: June 2016

AbstractTwo new π‐conjugated polymers, namely poly(p‐phenylenevinylene‐1,3,4‐oxadiazole) (PPVO) and poly(p‐(nitro‐phenylene)vinylene‐1,3,4‐oxadiazole) (PNPVO), were synthesized and characterized. The Gilch polymerization technique, using dihalo derivatives of 1,3,4‐oxadiazoles, was employed to synthesize them under mild reaction conditions. The macromolecules exhibit good solubility in dimethylformamide, formamide and dimethyl sulfoxide and thus effectively address the insolubility issues associated with many oxadiazole derivatives for device fabrication. They show bright luminescence in the blue‐green region of the electromagnetic spectrum and have optical band gaps suited for an emissive layer in organic light‐emitting devices. PPVO and PNPPO show good non‐linear optical responses also in solution phase, with third‐order nonlinear susceptibilities of the order of 10−12esu. Interestingly, they exhibit good antimicrobial characteristics under examination with Escherichia coli and Staphylococcus. The results prove that these macromolecules are ideal materials to use as emissive layers in various light‐emitting devices and NLO applications. The excellent antimicrobial activity can be utilized for their applications in clinical and healthcare areas. © 2016 Society of Chemical Industry
Lithium purification from aqueous solutions using bioinspired redox‐active melanin membranes
Authors: Park Hang‐Ah , Kim Young Jo , Kwon Ik Soo , Klosterman Luke , Bettinger Christopher J 
Published: June 2016

AbstractThe separation of lithium from magnesium ions in salt brines is an important step in producing raw lithium for prospective use in electrochemical storage systems. Liquid–liquid extraction of Mg2+ ions from Li+ ions is challenging because of comparable thermodynamic behavior in aqueous solutions. Removing Mg2+ ions from brines using consumable ion‐exchange membranes is also a challenging prospect due to poor chemical selectivity and compromised sustainability. Here, we propose the use of redox‐active catechols in the form of melanin pigments for selective removal of Mg2+ ions from aqueous solutions. Synthetic melanin films are oxidatively polymerized on stainless steel meshes from aqueous solutions of dopamine precursors to create electrochemically functionalized polydopamine membranes. The binding selectivity of redox‐active catechol‐bearing polydopamine melanin for Mg2+ ions in aqueous solutions was measured as a function of electrochemical cycling. The binding kinetics of Mg2+ ions to polydopamine pigments was measured. Mg2+ ions binding selectivity to polydopamine in mixed aqueous solutions containing both Li+ and Mg2+ ions were also measured. Additionally, the equilibrium binding concentrations of Mg2+ ions to polydopamine were achieved very rapidly (<1 min). Redox‐active polydopamine membranes therefore show promise as functional materials for the separation of Mg2+ and Li+ ions in aqueous solutions. © 2016 Society of Chemical Industry
Melanin synthesis under oxygen pressure
Authors: Bronze‐Uhle Erika Soares , Paulin João Vitor , Piacenti‐Silva Marina , Battocchio Chiara , Rocco Maria Luiza Miranda , Graeff Carlos Frederico de Oliveira 
Published: June 2016

AbstractMelanins are promising materials for organic bioelectronics devices like transistors, sensors and batteries. In this study, the chemical structural changes of melanin synthesized by the auto‐oxidation of l‐3,4‐dihydroxyphenylalanine (l‐DOPA) were analyzed for a new synthetic procedure that uses oxygen under pressure (4−8 atm). TEM, dynamic light scattering, Fourier transform IR, NMR and X‐ray photoelectron spectroscopy were used to characterize the material. Under oxygen pressure, melanin synthesis is accelerated; the polymer obtained is found to have structural differences, most notably a higher number of carbonyl groups and different surface charges compared to conventional synthetic melanin. As a consequence it has higher homogeneity and is soluble in water. To explain these findings a reaction mechanism is proposed based on current melanogenesis models. © 2016 Society of Chemical Industry
Polycarbazole by chemical oxidative interfacial polymerization: morphology and electrical conductivity based on synthesis conditions
Authors: Sangwan Watchara , Paradee Nophawan , Sirivat Anuvat 
Published: June 2016

AbstractPolycarbazole (PCB) was synthesized via an interfacial polymerization method using carbazole monomer and ammonium persulfate as the oxidizing agent. The effects of surfactant type (non‐ionic Tween 20, cationic cetyltrimethylammonium bromide (CTAB) and anionic sodium dodecylsulfate) and concentration on the synthesized PCB were investigated based on the roles of micelle formation. Electron microscopy images revealed various PCB morphologies depending on the surfactant type and concentration. The newly found morphological structures of the PCB were macroporous honeycomb, connected hollow sphere and smaller hollow sphere depending on the surfactant type. The highest electrical conductivity of doped PCB_CTAB obtained was 11.3 ± 0.36 S cm−1. The electrical conductivity values of the doped PCB synthesized with CTAB were higher than that without a surfactant by three orders of magnitude. © 2016 Society of Chemical Industry
A versatile synthetic path to thiol containing polysiloxanes
Authors: Perju Elena , Dünki Simon J. , Opris Dorina M. 
Published: June 2016

ABSTRACTA synthetic strategy to polydimethylsiloxanes and polymethylsiloxanes containing thiol functions as end‐ or side‐groups, respectively, is presented. Such polymers are important starting materials for elastomeric networks and postpolymerization modifications. The synthesis starts either with vinyl end‐functionalized polydimethylsiloxanes or with polymethylvinylsiloxanes. The vinyl groups are reacted either with thioacetic acid or with a thioacetic acid/butanethiol mixture via a UV‐initiated thiol‐ene reaction to form the respective thioester quantitatively within few minutes. The thioesters are subsequently deprotected to the respective thiols by reduction with LiAlH4. The resulting thiol containing polysiloxanes can be used for the formation of networks or another functionalization. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 2940–2948
Characterization of the structure and catalytic activity of Legionella pneumophila VipF
Authors: Young Byron H. , Caldwell Tracy A. , McKenzie Aidan M. , Kokhan Oleksandr , Berndsen Christopher E. 
Published: June 2016

ABSTRACTThe pathogenic bacteria Legionella pneumophila is known to cause Legionnaires' Disease, a severe pneumonia that can be fatal to immunocompromised individuals and the elderly. Shohdy et al. identified the L. pneumophila vacuole sorting inhibitory protein VipF as a putative N‐acetyltransferase based on sequence homology. We have characterized the basic structural and functional properties of VipF to confirm this original functional assignment. Sequence conservation analysis indicates two putative CoA‐binding regions within VipF. Homology modeling and small angle X‐ray scattering suggest a monomeric, dual‐domain structure joined by a flexible linker. Each domain contains the characteristic beta‐splay motif found in many acetyltransferases, suggesting that VipF may contain two active sites. Docking experiments suggest reasonable acetyl‐CoA binding locations within each beta‐splay motif. Broad substrate screening indicated that VipF is capable of acetylating chloramphenicol and both domains are catalytically active. Given that chloramphenicol is not known to be N‐acetylated, this is a surprising finding suggesting that VipF is capable of O‐acetyltransferase activity. Proteins 2016; 84:1422–1430. © 2016 Wiley Periodicals, Inc.
Delivery strategies: RNA interference in agriculture and human health
Authors: Heidebrecht Richard W 
Published: June 2016

AbstractCrop protection through expression of introduced insecticidal proteins is a well‐established technique. Modifications of endogenous gene expression have also been used successfully to produce safe and effective agrochemical products. The existing gene expression regulatory apparatus can be employed to alter messenger ribonucleic acid (mRNA) stability in the host species through a ribonucleic acid interference (RNAi) mechanism. Such solutions are currently delivered by incorporation of new genes into the host plant. Direct delivery of RNAi is being extensively explored in the clinic to treat selected human diseases and could be advantageous in agriculture. What are the unifying characteristics of successful delivery agents, and how can we project those observations into the future? © 2016 Society of Chemical Industry
Developing Modified Graphene Oxide Based Sensor for Lead Ions Detection in Water
Authors: Wang Xiaozhou , Jia Baoping , Zhang Wei , Lin Bencai , Wang Qiuze , Ding Jianning 
Published: June 2016

AbstractBlade coating method was employed to fabricate the pure graphene oxide sensors, whose sensitivity turned out to be about 10−9 M for detection of lead ions (Pb2+). To improve its ability to detect Pb2+ at much lower concentration, modification with 50–200 nm Au nanoparticles (AuNPs) was performed on graphene oxide based on the fact that Pb2+ could accelerate the leaching rate of AuNPs on the surface of graphene by S2O32− and 2‐mercaptoethanel (2‐ME), leading to the sensitivity improved over 2 order magnitude, as well as excellent selectivity toward lead ions over a wide range of other metal ions. The approach and findings presented in this paper could also be extended to the fabrication of other heavy metal ions sensors and the improvement of their performances.
Fluorescence Quenching of a Benzimidazolium–based Probe for Selective Detection of Picric Acid in Aqueous Medium
Authors: Joshi Sunita , Kumari Santosh , Chamorro Eduardo , Pant Debi D. , Sakhuja Rajeev 
Published: June 2016

AbstractA fluorescent coumaryl linked benzimidazolium salt has been synthesized, characterized and found to be highly selective for nanomolar detection of commonly used explosive picric acid, over other aromatic explosives in aqueous medium. The quenching constant and detection limit of the sensor for picric acid was found to be KSV=1.58 × 104 M−1 and 208 nM respectively. The high sensitivity of the sensor toward picric acid can be predominantly attributed to the ground‐state charge‐transfer complex formation based on UV‐visible studies, time resolved fluorescence results and Density Functional Theory (DFT) calculations.
Early elementary students’ understanding of complex ecosystems: A learning progression approach
Authors: Hokayem Hayat , Gotwals Amelia Wenk 
Published: June 2016

AbstractEngaging in systemic reasoning about ecological issues is critical for early elementary students to develop future understanding of critical environmental issues such as global warming and loss of biodiversity. However, ecological issues are rarely taught in ways to highlight systemic reasoning in elementary schools. In this study, we conducted semi‐structured interviews with 44 students from the first through fourth grades. Using an iterative process, we developed an empirically grounded learning progression that captures how elementary students use systemic reasoning to explain interactions in ecosystems. This learning progression contains five reasoning patterns: anthropomorphic reasoning, concrete practical reasoning, simple causal reasoning, semi‐complex causal reasoning, and complex causal reasoning. The results also show that many students exhibited mixed‐level reasoning, meaning that they used reasoning patterns at multiple levels to construct a single response. We discuss the implications of the study for learning progression research and teaching ecosystems at early elementary grades. © 2016 Wiley Periodicals, Inc. J Res Sci Teach 53: 1524–1545, 2016
The association between pulse pressure change and cognition in late life: Age and where you start matters
Authors: McDade Eric , Sun Zhaowen , Lee Ching‐Wen , Snitz Beth , Hughes Tiffany , Chang Chung‐Chou H. , Ganguli Mary 
Published: June 2016

AbstractIntroductionVariations across studies in the association between blood pressure (BP) and cognition might be explained partly by duration of exposure to hypertension and partly by nonrandom attrition over time. Pulse pressure (PP) reflects arterial stiffness which may better reflect chronicity of hypertension.MethodsOver six annual cycles, 1954 individuals aged 65+ years from a prospective population‐based cohort underwent BP measurements and cognitive evaluations. We examined the relationship of change in five cognitive domains to longitudinal PP patterns across the late‐life age spectrum, before and after stratifying by baseline systolic blood pressure (SBP) and adjusting for attrition.ResultsThere were four longitudinal PP patterns: stable normal, stable high, increasing, and decreasing. Those with lower baseline SBP and an increasing or stable high PP had less decline in cognition, an effect that was attenuated with aging. Among those with higher baseline SBP, there were no differences across PP groups, but increasing age was consistently associated with greater cognitive decline.DiscussionThe effect of PP on cognitive decline depends on age, baseline SBP, and the trajectory of PP change. Cardiovascular mechanisms underlying cognitive aging should be recognized as nuanced and dynamic processes when exploring prevention and treatment targets in the elderly, so that the optimal timing and type of intervention can be identified.
P.009 Physician assisted death and the neurosurgeon
Authors: Barry SP , Fleetwood I , Reddy K , Ekong C , Gorman P , Wheelock B , Moulton R 
Published: June 2016

Background: The Supreme Court of Canada (SCC) recently rendered a decision striking down the Criminal Code absolute prohibition on providing assisted dying. End of life decisions are commonly encountered by neurosurgeons due to the nature of their practice. Neurosurgeons will be faced with patients requesting PAD in the near future. Methods: The recent SCC ruling heralds a change that will radically alter a most basic tenet that has historically guided physicians and surgeons. A subcommittee of the Canadian Neurosurgical Society (CNSS) was formed to generate a position statement to reflect the interests of both neurosurgeons and their patients. Results: Fundamental issues regarding the implementation of PAD identified include:Clarity of legislationThe creation of an independent, third party referral serviceEffective safeguards and oversight of the entire process-The right to “conscientious objection” on the part of hysicians who do not wish to be involved in PADConclusions: The CNSS urges clarity in legislation regarding PAD and strict oversight in its implementation to reduce potential harm. We also support the creation of an independent, third party referral service which would serve to respect the conscience of those health care providers who do not wish to actively participate in PAD.
A.06 Ataluren: an overview of clinical trial results in nonsense mutation Duchenne Muscular Dystrophy (nmDMD)
Authors: McDonald CM , Bushby K , Tulinius M , Finkel R , Topaloglu H , Day JW , Flanigan K , Lowes L , Eagle M , Luo X , Elfring G , Kroger H , Riebling P , Ong T , Spiegel R , Peltz SW 
Published: June 2016

Background: Ataluren is the first drug to treat the underlying cause of nmDMD. Methods: Phase 2 and 3 studies of ataluren in nmDMD were reviewed, with efficacy and safety/tolerability findings summarized. Results: Ataluren nmDMD trials include: a Phase 2a proof-of-concept study (N=38); a Phase 2b randomized controlled trial (RCT) (N=174); an ongoing US-based open-label safety extension study (N=108); an ongoing non-US-based open-label safety/efficacy extension study (N=94); and a Phase 3 RCT, ACT DMD (N=228), whose primary endpoint was change in six-minute walk distance (6MWD) over 48 weeks. The proof-of-concept study demonstrated increased dystrophin production in post-treatment muscle biopsies from ataluren-treated patients with nmDMD. The Phase 2b results demonstrated an ataluren treatment effect in 6MWD, timed function tests, and other measures of physical functioning, The Phase 3 ACT DMD results demonstrated an ataluren treatment effect in patients with nmDMD in both primary and secondary endpoints, particularly in those with a baseline 6MWD of 300-400m. Ataluren was consistently well-tolerated in all three trials, as well as in the ongoing extension studies. Trial findings will be presented in detail. Conclusions: The totality of the results demonstrates that ataluren enables nonsense mutation readthrough in the dystrophin mRNA, producing functional dystrophin and slowing disease progression.Supported by: PTC Therapeutics Inc.
Biological approaches to characterize the mode of action of two 5-nitroindazolinone prototypes onTrypanosoma cruzibloodstream trypomastigotes
Authors: FONSECA-BERZAL CRISTINA , DA SILVA CRISTIANE FRANÇA , MENNA-BARRETO RUBEM F. S. , BATISTA MARCOS MEUSER , ESCARIO JOSÉ A. , ARÁN VICENTE J. , GÓMEZ-BARRIO ALICIA , SOEIRO MARIA DE NAZARÉ C. 
Published: June 2016

SUMMARYThe phenotypic activity of two 5-nitroindazolinones, i.e. 2-benzyl-1-propyl (22) and 2-benzyl-1-butyl (24) derivatives, previously proposed as anti-Trypanosoma cruziprototypes, was presently assayed on bloodstream trypomastigotes (BT) of the moderately drug-resistant Y strain. Further exploration of putative targets and cellular mechanisms involved in their activity was also carried out. Therefore, transmission electron microscopy, high-resolution respirometry and flow cytometry procedures were performed on BT treated for up to 24 h with the respective EC50value of each derivative. Results demonstrated that although 22 and 24 were not as active as benznidazole in thisin vitroassay on BT, both compounds triggered important damages inT. cruzithat lead to the parasite death. Ultrastructural alterations included shedding events, detachment of plasma membrane and nuclear envelope, loss of mitochondrial integrity, besides the occurrence of a large number of intracellular vesicles and profiles of endoplasmic reticulum surrounding cytoplasmic organelles such as mitochondrion. Moreover, both derivatives affected mitochondrion leading to this organelle dysfunction, as reflected by the inhibition in oxygen consumption and the loss of mitochondrial membrane potential. Altogether, the findings exposed in the present study propose autophagic processes and mitochondrial machinery as part of the mode of action of both 5-nitroindazolinones 22 and 24 onT. cruzitrypomastigotes.
Immunodiagnostic monoclonal antibody-based sandwich ELISA of fasciolosis by detection ofFasciola giganticacirculating fatty acid binding protein
Authors: ANURACPREEDA PANAT , CHAWENGKIRTTIKUL RUNGLAWAN , SOBHON PRASERT 
Published: June 2016

SUMMARYUp to now, parasitological diagnosis of fasciolosis is often unreliable and possesses low sensitivity. Hence, the detection of circulating parasite antigens is thought to be a better alternative for diagnosis of fasciolosis, as it reflects the real parasite burden. In the present study, a monoclonal antibody (MoAb) against recombinantFasciola giganticafatty acid binding protein (rFgFABP) has been produced. As well, a reliable sandwich enzyme-linked immunosorbent assay (sandwich ELISA) has been developed for the detection of circulating FABP in the sera of mice experimentally and cattle naturally infected withF. gigantica. MoAb 3A3 and biotinylated rabbit anti-recombinant FABP antibody were selected due to their high reactivities and specificities. The lower detection limit of sandwich ELISA was 5 pg mL−1, and no cross-reaction with other parasite antigens was observed. This assay could detectF. giganticainfection from day 1 post infection. In experimental mice, the sensitivity, specificity and accuracy of this assay were 93·3, 100 and 98·2%, while in natural cattle they were 96·7, 100 and 99·1%. Hence, this sandwich ELISA method showed high efficiencies and precisions for diagnosis of fasciolosis byF. gigantica.
Factors associated with recovery of meat products following recalls due to Shiga toxin-producing Escherichia coli
Authors: SEYS S. A. , SAMPEDRO F. , HEDBERG C. W. 
Published: June 2016

SUMMARYFood-product recall data for recalls due to Shiga toxin-producing Escherichia coli (STEC) from 2000 to 2012 were obtained for establishments regulated by the United States Department of Agriculture, Food Safety and Inspection Service (FSIS). Statistical tests were used to assess the factors associated with recovery of product following STEC recalls along with the relationship between cluster detection and jurisdictions. Our results indicated that the percentage of recalled product recovered following a recall action due to STEC was dependent on the complexity of distribution, type of distribution, amount of time between production and recall dates, and the number of pounds of product recalled. Illness-related STEC recalls were associated with a lower percentage of product recovery which was probably impacted by larger amounts of product recalled, broader production scope, and delays from epidemiological and traceback investigations. Further, detection of illnesses related to STEC recalls seemed to be enhanced in states with additional resources and a history of successful foodborne investigations. This makes an argument for additional resources dedicated to public health agencies specifically for the surveillance of foodborne illnesses.
Cumulative context effects and variant lexical representations: Word use and English final t/d deletion
Authors: Raymond William D. , Brown Esther L. , Healy Alice F. 
Published: June 2016

AbstractWord production variability is widespread in speech, and rates of variant production correlate with many factors. Recent research suggests mental representation of both canonical word forms and distinct reduced variants, and that production and processing are sensitive to variant frequency. What factors lead to frequency-weighted variant representations? An experiment manipulated following context and word repetition for final t/d words in read, narrative English speech. Modeling the experimentally generated data statistically showed higher final-segment deletion in tokens followed by consonant-initial words, but no evidence of increased deletion with repetition, regardless of context. Deletion rates were also higher the greater a word's cumulative exposure to consonant contexts (measured from distributional statistics), but there was no effect of word frequency. Token effects are interpreted in terms of articulation processes. The type-level context effect is interpreted within exemplar and usage-based models of language to suggest that experiences with word variants in contexts register as frequency-weighted representations.