bluuebunny/crossref_metadata_2025_split huggingface dataset:
Highly Fluorescent Green Fluorescent Protein Chromophore Analogues Made by Decorating the Imidazolone Ring
Authors: Gutiérrez Sara , Martínez‐López David , Morón María , Sucunza David , Sampedro Diego , Domingo Alberto , Salgado Antonio , Vaquero Juan J. 
Published: November 2015

AbstractThe synthesis and photophysical behavior of an unexplored family of green fluorescent protein (GFP)‐like chromophore analogues is reported. The compound (Z)‐4‐(4‐hydroxybenzylidene)‐1‐propyl‐2‐(propylamino)‐1H‐imidazol‐5(4 H)‐one (p‐HBDNI, 2 a) exhibits significantly enhanced fluorescence properties relative to the parent compound (Z)‐5‐(4‐hydroxybenzylidene)‐2,3‐dimethyl‐3,5‐dihydro‐4H‐imidazol‐4‐one (p‐HBDI, 1). p‐HBDNI was considered as a model system and the photophysical properties of other novel 2‐amino‐3,5‐dihydro‐4H‐imidazol‐4‐one derivatives were evaluated. Time‐dependent DFT calculations were carried out to rationalize the results. The analogue AIDNI (2 c), in which the 4‐hydroxybenzyl group of p‐HBDNI was replaced by an azaindole group, showed improved photophysical properties and potential for cell staining. The uptake and intracellular distribution of 2 c in living cells was investigated by confocal microscopy imaging.
Diversity Oriented Synthesis of Indoloazepinobenzimidazole and Benzimidazotriazolobenzodiazepine from N1‐Alkyne‐1,2‐diamines
Authors: Kumar Ravi , Arigela Rajesh K. , Samala Srinivas , Kundu Bijoy 
Published: November 2015

AbstractA one‐pot protocol for the diversity oriented synthesis of two N‐polyheterocycles indoloazepinobenzimidazole and benzimidazotriazolobenzodiazepine from a common N1‐alkyne‐1,2‐diamine building block is described. The approach involves sequential formation of benzimidazole through cyclocondensation and oxidation, which is followed by the formation of either an azepine ring (through alkyne activation and 6‐endo‐dig cyclization, 1,2‐migration with ring expansion, and re‐aromatization), or diazepine and triazole rings through 1,3‐dipolar cycloaddition.
Functional Hallmarks of a Catalytic DNA that Makes Lariat RNA
Authors: Javadi‐Zarnaghi Fatemeh , Höbartner Claudia 
Published: November 2015

AbstractCatalytic DNAs, also known as deoxyribozymes, are of practical value for the synthesis of structurally or topologically complex RNAs, but little is known about the molecular details of DNA catalysis. We have investigated a deoxyribozyme that catalyzes the formation of a specific intramolecular 2′,5′‐phosphodiester bond to produce lariat RNA, which is an important biological intermediate in eukaryotic mRNA splicing. The results of combinatorial mutation interference analysis (CoMA) allowed us to shrink the catalytic core to 70 % of its original length and revealed that the essential part of the deoxyribozyme sequence contained more than 50 % guanosines. Nucleotide analogue interference mapping (dNAIM) and dimethyl sulfate interference (DMSi) experiments provided atomic details of individual guanosine functional groups. Additional spectroscopic experiments and structural probing data identified conformational changes upon metal‐ion binding and catalysis. Overall, this comprehensive analysis of the DNA‐catalyzed reaction has provided specific insights into the synthesis of 2′,5′‐branched RNA, and suggested the general features of deoxyribozymes that catalyze nucleic acid ligation reactions.
Polyaromatic Profluorescent Nitroxide Probes with Enhanced Photostability
Authors: Lussini Vanessa C. , Blinco James P. , Fairfull‐Smith Kathryn E. , Bottle Steven E. 
Published: November 2015

AbstractNovel profluorescent mono‐ and bis‐isoindoline nitroxides linked to napthalimide and perylene diimide structural cores are described. These nitroxide‐fluorophore probes display strongly suppressed fluorescence in comparison to their corresponding non‐radical diamagnetic methoxyamine derivatives. The perylene‐based probe possessing two isoindoline systems tethered through ethynyl linkages was shown to be the most photostable in solution, demonstrating significantly enhanced longevity over the 9,10‐bis(phenylethynyl)anthracene fluorophore used in previous profluorescent nitroxide probes.
Influence of pH on the Motion of Catalytic Janus Particles and Tubular Bubble‐Propelled Micromotors
Authors: Moo James Guo Sheng , Wang Hong , Pumera Martin 
Published: November 2015

AbstractSelf‐propelled miniaturized machines harness the chemical potential of their environment for movement. Locomotion of chemically powered micromotors have been hugely dependent on the surroundings. The use of pH to alter the mobility of micromotors is demonstrated in this work through the manipulation of hydrogen peroxide chemistry in different acidity/alkalinity. The sequential addition of sodium hydroxide to increase the pH of the solution led to a consequent increase in activity of micromotors. Meanwhile, addition of hydrochloric acid compromised the structural integrity of the microstructures, culminating in locomotive changes. Such dramatic changes in activity and velocities of the micromotors allow the usage of this behavior for pH detection. This concept was illustrated with Janus silver micromotors and tubular bimetallic Cu/Pt micromotors. Alteration of pH serves as a useful general strategy for increasing hydrogen peroxide decomposition for enhanced oxygen‐bubble propulsion in catalytic micromotors.
Towards Clarifying the Role of O2 during the Phthalocyanine Synthesis
Authors: Wang Kang , Pan Houhe , Jiang Jianzhuang 
Published: November 2015

AbstractThe role of O2 within the synthesis of phthalocyanines (Pcs) has remained unclear in the past century. Here, we demonstrate that O2, in cooperation with the solvent n‐pentanol, participates in the cyclic tetramerization of phthalonitriles over the half‐sandwich complex template [Lu(Pc)(acac)] (acac=acetylacetonate) and terminates the reaction at the stage of uncyclized isoindole oligomeric derivatives rather than the phthalocyanine chromophores, resulting in the isolation of the heteroleptic (phthalocyaninato)(triisoindole‐1‐one) lutetium double‐decker complexes [(Pc)Lu(TIO‐I)] (TIO‐I=3,4,7,8,11,12‐sexi(2,6‐diisopropylphenoxy)‐15‐[4,5‐di(2,6‐diisopropylphenoxy)‐2‐cyanobenzimidamido]triisoindole‐1‐one) and [(Pc)Lu(TIO‐II)] (TIO‐II=3,4,7,8,11,12‐sexi(2,6‐dimethylphenoxy)‐15‐[4,5‐di(2,6‐dimethylphenoxy)‐2‐cyanobenzimidamido]triisoindole‐1‐one) with the help of bulky substituents at the phthalonitrile periphery and an unsubstituted phthalocyanine ligand in the double‐decker skeleton. Nevertheless, the cyclic tetramerization of the phthalonitriles was revealed to be sensitive to O2 with the reaction progression also depending on the oxygen concentration/content, leading to the O2‐senstive and ‐dependent nature for the isolation of phthalocyanine derivatives.
Strategy Approach for Direct Enantioseparation of Hyoscyamine Sulfate and Zopiclone on a Chiral αl‐Acid Glycoprotein Column and Determination of Their Eutomers: Thermodynamic Study of Complexation
Authors: Zaazaa Hala E. , Salama Nahla N. , Abd El Halim Lobna M. , Salem Maissa Y. , Abd El Fattah Laila E. 
Published: November 2015

AbstractRapid and simple isocratic high‐performance liquid chromatographic methods with UV detection were developed and validated for the direct resolution of racemic mixtures of hyoscyamine sulfate and zopiclone. The method involved the use of αl‐acid glycoprotein (AGP) as chiral stationary phase. The stereochemical separation factor (ά) and the stereochemical resolution factor (Rs) obtained were 1.29 and 1.60 for hyoscyamine sulfate and 1.47 and 2.45 for zopiclone, respectively. The method was used for determination of chiral switching (eutomer) isomers: S‐hyoscyamine sulfate and eszopiclone. Several mobile phase parameters were investigated for controlling enantioselective retention and resolution on the chiral AGP column. The influence of mobile phase, concentration and type of uncharged organic modifier, ionic strength, and column temperature on enantioselectivity were studied. Calibration curves were linear in the ranges of 1–10 µg mL‐1 and 0.5–5 µg mL‐1 for S‐hyoscyamine sulfate and eszopiclone, respectively. The method is specific and sensitive, with lower limits of detection and quantifications of 0.156, 0.515 and 0.106, 0.349 for S‐hyoscyamine sulfate and eszopiclone, respectively. The method was used to identify quantitatively the enantiomers profile of the racemic mixtures of the studied drugs in their pharmaceutical preparations. Thermodynamic studies were performed to calculate the enthalpic ΔH and entropic ΔS terms. The results showed that enantiomer separation of the studied drugs were an enthalpic process. Chirality 28:49–57, 2016. © 2015 Wiley Periodicals, Inc.
Enantiopure Indolizinoindolones with in vitro Activity against Blood‐ and Liver‐Stage Malaria Parasites
Authors: Pereira Nuno A. L. , Monteiro Ângelo , Machado Marta , Gut Jiri , Molins Elies , Perry M. Jesus , Dourado Jorge , Moreira Rui , Rosenthal Philip J. , Prudêncio Miguel , Santos Maria M. M. 
Published: November 2015

AbstractMalaria continues to be a major cause of morbidity and mortality to this day, and resistance to drugs like chloroquine has led to an urgent need to discover novel chemical entities aimed at new targets. Here, we report the discovery of a novel class of potential antimalarial compounds containing an indolizinoindolone scaffold. These novel enantiopure indolizinoindolones were synthesized, in good‐to‐excellent yields and excellent diastereoselectivities, by cyclocondensation reaction of (S)‐ or (R)‐tryptophanol and 2‐acyl benzoic acids, followed by intramolecular α‐amidoalkylation. Interestingly, we were able to synthesize for the first time 7,13b‐cis indolizinoindolones in a two‐step route. The novel compounds showed promising activity against erythrocytic stages of the human malaria parasite, Plasmodium falciparum, and liver stages of the rodent parasite Plasmodium berghei. In particular, an (S)‐tryptophanol‐derived isoindolinone was identified as a promising starting scaffold to search for novel antimalarials, combining excellent activity against both stages of the parasite′s life cycle with low cytotoxicity and excellent metabolic and chemical stability in vitro.
Design of PID controllers using Filippov's method for stable operation of DC–DC converters
Authors: Hayes Brendan , Condon Marissa , Giaouris Damian 
Published: November 2015

SummaryA lot of work has taken place into the design and control of DC–DC converters, and various methodologies have been proposed. While traditionally only P or PI controllers have been employed, recent applications that require a fast transient performance impose the usage of the derivative, D, term. As it is well known, using the D‐term can cause numerous problems in such converters that greatly downgrade their performance and lifetime. Having said that, in this paper, we first prove that by using the D‐term, it is possible to increase the stability margin (and hence keep a low current ripple), and then, we present a novel method to tune the PID controller that guarantees a fast and stable response over a wide range of parameter values without using an unreasonably high value of the derivative gain that magnifies the presence of noise in the system. The controller is designed utilising Filippov's method, and a simple and easy to implement strategy is proposed. Furthermore, an adaptive PID controller is designed whose gains are changed depending on the value of the supply voltage or output load. Another important contribution of this work is the derivation of the saltation matrix when the switching manifold is discontinuous, the complete proof is presented, and the results validated. Copyright © 2015 John Wiley & Sons, Ltd.
Expression of CD2 and CD25 on mast cell populations can be seen outside the setting of systemic mastocytosis
Authors: Cherian Sindhu , McCullouch Vivian , Miller Valerie , Dougherty Katy , Fromm Jonathan R. , Wood Brent L. 
Published: November 2015

BackgroundSystemic mastocytosis (SM) is a diagnosis made using clinical, laboratory, and histologic parameters. Aberrant CD2 and/or CD25 expression on mast cells provides one minor criterion for a diagnosis of SM. To validate a tube (CD45/CD117/CD2/CD25) for mast cell evaluation, flow cytometry (FC) on residual material from marrow aspirates samples submitted to the hematopathology laboratory was performed.MethodsSamples evaluated (n = 98) had no clinical or morphologic suspicion for SM. Samples were excluded if there was history of a myeloid stem cell neoplasm. Ten documented cases of SM were evaluated for comparison.ResultsAmong cases without history of SM, 17.3% (n = 17) showed expression of CD2 and/or CD25 on ≥10% of the mast cell population (CD25 alone in 14 cases, CD2 alone in 2 cases, both in one case), while 82.6% (n = 81) showed no expression of these antigens. The percentage of mast cells showing aberrant CD2 and/or CD25 expression respectively ranged from 12.1% to 98.8% and 22.2% to 95.7% Interestingly, all of the cases with evidence of aberrant antigen expression on mast cells were collected post‐therapy while 22.1% of the negative samples were collected pre‐therapy. A cut‐off of 60% CD25 expression on mast cells identified all cases of SM while minimizing false positives.ConclusionsThese findings demonstrate that aberrant expression of CD2 and/or CD25 may be seen on mast cells outside of the setting of SM. The data suggests that this phenomenon may be seen more commonly following chemotherapy and that FC of mast cells should be interpreted with caution in the post‐chemotherapy setting. © 2015 International Clinical Cytometry Society
Temporal and spatial requirements for Nodal‐induced anterior mesendoderm and mesoderm in anterior neurulation
Authors: Gonsar Ngawang , Coughlin Alicia , Clay‐Wright Jessica A. , Borg Bethanie R. , Kindt Lexy M. , Liang Jennifer O. 
Published: November 2015

SummaryZebrafish with defective Nodal signaling have a phenotype analogous to the fatal human birth defect anencephaly, which is caused by an open anterior neural tube. Previous work in our laboratory found that anterior open neural tube phenotypes in Nodal signaling mutants were caused by lack of mesendodermal/mesodermal tissues. Defects in these mutants are already apparent at neural plate stage, before the neuroepithelium starts to fold into a tube. Consistent with this, we found that the requirement for Nodal signaling maps to mid‐late blastula stages. This timing correlates with the timing of prechordal plate mesendoderm and anterior mesoderm induction, suggesting these tissues act to promote neurulation. To further identify tissues important for neurulation, we took advantage of the variable phenotypes in Nodal signaling‐deficient sqt mutant and Lefty1‐overexpressing embryos. Statistical analysis indicated a strong, positive correlation between a closed neural tube and presence of several mesendoderm/mesoderm‐derived tissues (hatching glands, cephalic paraxial mesoderm, notochord, and head muscles). However, the neural tube was closed in a subset of embryos that lacked any one of these tissues. This suggests that several types of Nodal‐induced mesendodermal/mesodermal precursors are competent to promote neurulation. genesis 54:3–18, 2016. © 2016 Wiley Periodicals, Inc.
Synthesis and Evaluation of the Antiproliferative Properties of a Tethered Tubercidin–Platinum(II) Complex
Authors: D'Errico Stefano , Oliviero Giorgia , Borbone Nicola , Di Gennaro Elena , Zotti Andrea Ilaria , Budillon Alfredo , Cerullo Vincenzo , Nici Fabrizia , Mayol Luciano , Piccialli Vincenzo , Piccialli Gennaro 
Published: November 2015

AbstractHerein, the synthesis of a nucleoside platinum(II) complex in which a cisplatin‐like unit is joined to 7‐deazaadenosine through an amino alkyl chain installed at the C6 position of purine was explored. The capability of the new complex to react with DNA purine bases was confirmed by a model reaction with deoxyguanosine monophosphate, whereas its antiproliferative activity against A549 and Cal27 human cancer cell lines was studied by sulforhodamine B assay in comparison with its unplatinated precursor and cisplatin.
Development of Nonenzymatic Hydrogen Peroxide Sensor Based on Successive Pd‐Ag Electrodeposited Nanoparticles on Glassy Carbon Electrode
Authors: Roushani Mahmoud , Dizajdizi Behruz Zare 
Published: November 2015

AbstractA novel strategy to fabricate hydrogen peroxide (H2O2) sensor was developed by electrodepositing palladiumsilver nanoparticles (NPs) on a glassy carbon electrode. The morphology of the modified electrode was characterized by Scanning electron microscopy (SEM). The result of electrochemical experiments showed that such constructed sensor had a favorable catalytic ability, high sensitivity, excellent selectivity towards reduction of hydrogen peroxide (H2O2). The response to H2O2 is linear in the range between 0.30 μM to 2.50 mM, and the detection limit is 0.1 μM (at an S/N of 3).
Markovian modeling of seismic damage accumulation
Authors: Iervolino Iunio , Giorgio Massimiliano , Chioccarelli Eugenio 
Published: November 2015

SummaryAnalysis of civil structures at the scale of life‐cycle requires stochastic modeling of degradation. Phenomena causing structures to degrade are typically categorized as aging and point‐in‐time overloads. Earthquake effects are the members of the latter category this study deals with in the framework of performance‐based earthquake engineering (PBEE). The focus is structural seismic reliability, which requires modeling of the stochastic process describing damage progression, because of subsequent events, over time. The presented study explicitly addresses this issue via a Markov‐chain‐based approach, which is able to account for the change in seismic response of damaged structures (i.e. state‐dependent seismic fragility) as well as uncertainty in occurrence and intensity of earthquakes (i.e. seismic hazard). The state‐dependent vulnerability issue arises when the seismic hysteretic response is evolutionary and/or when the damage measure employed is such that the degradation increment probabilistically depends on the conditions of the structure at the time of the shock. The framework set up takes advantage also of the hypotheses of classical probabilistic seismic hazard analysis, allowing to separate the modeling of the process of occurrence of seismic shocks and the effect they produce on the structure. It is also discussed how the reliability assessment, which is in closed‐form, may be virtually extended to describe a generic age‐ and state‐dependent degradation process (e.g. including aging and/or when aftershock risk is of interest). Illustrative applications show the options to calibrate the model and its potential in the context of PBEE. Copyright © 2015 John Wiley & Sons, Ltd.
Prevalence of pseudobulbar affect symptoms and clinical correlates in nursing home residents
Authors: Foley Kevin , Konetzka R. Tamara , Bunin Anthony , Yonan Charles 
Published: November 2015

ObjectivePseudobulbar affect (PBA) is a neurological disorder of emotional expression, characterized by uncontrollable episodes of crying or laughing in patients with certain neurological disorders affecting the brain. The purposes of this study were to estimate the prevalence of PBA in US nursing home residents and examine the relationship between PBA symptoms and other clinical correlates, including the use of psychopharmacological medications.MethodsA retrospective study was conducted between 2013 and 2014 with a convenience sample of residents from nine Michigan nursing homes. Chronic‐care residents were included in the “predisposed population” if they had a neurological disorder affecting the brain and no evidence of psychosis, delirium, or disruptive behavior (per chart review). Residents were screened for PBA symptoms by a geropsychologist using the Center for Neurologic Study‐Lability Scale (CNS‐LS). Additional clinical information was collected using a diagnostic evaluation checklist and the most recent Minimum Data Set 3.0 assessment.ResultsOf 811 residents screened, complete data were available for 804, and 412 (51%) met the criteria for the “predisposed population.” PBA symptom prevalence, based on having a CNS‐LS score ≥13, was 17.5% in the predisposed population and 9.0% among all nursing home residents. Those with PBA symptoms were more likely to have a documented mood disorder and be using a psychopharmacological medication, including antipsychotics, than those without PBA symptoms.ConclusionsPseudobulbar affect symptoms were present in 17.5% of nursing home residents with neurological conditions, and 9.0% of residents overall. Increasing awareness and improving diagnostic accuracy of PBA may help optimize treatment. © 2015 The Authors. International Journal of Geriatric Psychiatry Published by John Wiley & Sons Ltd.
Differences in neural activity when processing emotional arousal and valence in autism spectrum disorders
Authors: Tseng Angela , Wang Zhishun , Huo Yuankai , Goh Suzanne , Russell James A. , Peterson Bradley S. 
Published: November 2015

AbstractIndividuals with autism spectrum disorders (ASD) often have difficulty recognizing and interpreting facial expressions of emotion, which may impair their ability to navigate and communicate successfully in their social, interpersonal environments. Characterizing specific differences between individuals with ASD and their typically developing (TD) counterparts in the neural activity subserving their experience of emotional faces may provide distinct targets for ASD interventions. Thus we used functional magnetic resonance imaging (fMRI) and a parametric experimental design to identify brain regions in which neural activity correlated with ratings of arousal and valence for a broad range of emotional faces. Participants (51 ASD, 84 TD) were group‐matched by age, sex, IQ, race, and socioeconomic status. Using task‐related change in blood‐oxygen‐level‐dependent (BOLD) fMRI signal as a measure, and covarying for age, sex, FSIQ, and ADOS scores, we detected significant differences across diagnostic groups in the neural activity subserving the dimension of arousal but not valence. BOLD‐signal in TD participants correlated inversely with ratings of arousal in regions associated primarily with attentional functions, whereas BOLD‐signal in ASD participants correlated positively with arousal ratings in regions commonly associated with impulse control and default‐mode activity. Only minor differences were detected between groups in the BOLD signal correlates of valence ratings. Our findings provide unique insight into the emotional experiences of individuals with ASD. Although behavioral responses to face‐stimuli were comparable across diagnostic groups, the corresponding neural activity for our ASD and TD groups differed dramatically. The near absence of group differences for valence correlates and the presence of strong group differences for arousal correlates suggest that individuals with ASD are not atypical in all aspects of emotion‐processing. Studying these similarities and differences may help us to understand the origins of divergent interpersonal emotional experience in persons with ASD. Hum Brain Mapp 37:443–461, 2016. © 2015 Wiley Periodicals, Inc.