bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Alkane Linker Length and Chalcogen Character in [FeFe]‐Hydrogenase Inspired Compounds
Authors: Harb Mohammad K. , Daraosheh Ahmad , Görls Helmar , Smith Elliott R. , Meyer G. Joel , Swenson Matthew T. , Sakamoto Takahiro , Glass Richard S. , Lichtenberger Dennis L. , Evans Dennis H. , El‐khateeb Mohammad , Weigand Wolfgang 
Published: September 2014

ABSTRACTModels of [FeFe]‐hydrogenases containing diselenolato ligands with different bridge linker length have been prepared: Fe2(μ‐Se(CH2)4Se‐μ)(CO)6 (4DS), and Fe2(μ‐Se(CH2)5Se‐μ)(CO)6 (5DS) as well as dithiolato Fe2(μ‐S(CH2)4S‐μ)(CO)6 (4DT) and compared with Fe2(μ‐S(CH2)3S‐μ)(CO)6 (PDT) and Fe2(μ‐Se(CH2)3Se‐μ)(CO)6 (PDS). Compounds 4DT, PDS, 4DS, and 5DS were characterized by spectroscopic techniques including NMR, IR, mass spectrometry, ultraviolet photoelectron spectroscopy (UPS), elemental analysis, and X‐ray crystal structure analysis. Combinations of electrochemical measurements, UPS, and density functional theory calculations indicate that oxidations of these five compounds are not significantly affected by chalcogen character but instead are governed by linker length. Cations for all compounds are calculated to adopt a bridged CO “rotated” structure with a vacant site on one of the Fe centers. In 4DT, 4DS, and 5DS, the alkane linker forms an agostic interaction with the vacant site on the rotated Fe. The reduction potentials for these compounds shift positively on average 0.16 V for each carbon added to the alkane linker with shifts being as large as 0.23 V between PDT and 4DT, and as small as 0.09 V between 4DS and 5DS. Catalytic reduction of protons from acetic acid in CH2Cl2 occurs at −1.79 and −1.86 V for PDT and 4DT and −2.02, −2.09, and −2.04 V for PDS, 4DS, and 5DS, indicating that chalcogen character is the primary factor that affects catalytic potential. On average the S‐containing compounds catalyze proton reduction at potentials, which are 0.23 V less negative than the Se‐containing compounds in this study.
How User Experience Changes over Time: A Case Study of Social Network Services
Authors: Kim Hyun K. , Han Sung H. , Park Jaehyun , Park Wonkyu 
Published: September 2014

AbstractWhile interacting with a product or a service, people have diverse experiences, which constitute user experience (UX). In this study, the hierarchical dimensions of UX were considered, including overall UX, its elements (usability, affect, and user value) and their subelements. To determine how UX changes over time, the temporal changes of the influence of each element and subelement were analyzed. Twenty subjects participated in a longitudinal experiment by using a social network service (SNS). The most important element of UX changed from usability to user value after one week of use. These results suggest that adoption of an SNS occurs in two phases: a phase of affected by usability and a phase affected by user value. Identification of these phases and the systematic approach used in the study are expected to contribute to design and evaluation of new SNSs and other products and services.
Simulating streamflow on regulated rivers using characteristic reservoir storage patterns derived from synthetic remote sensing data
Authors: Yoon Yeosang , Beighley Edward 
Published: September 2014

AbstractThis study presents a method to estimate streamflow in rivers regulated by lakes or reservoirs using synthetic satellite remote sensing data. To illustrate the approach, the new reservoir routing method is integrated into the Hillslope River Routing model, and a case study is presented for the highly regulated river in the Cumberland River basin (46,400 km2). The study period is April–May 2000, which contains a significant flood event that occurred in 1–2 May 2000. The model is shown to capture storage/release characterises in eight reservoirs with a mean normalized root mean square error (NRMSE) of 20% for entire simulation period and 27% for the May flood event. These errors are 69 and 75%, respectively, less than the NRMSE if reservoirs are not included in the model. Given the limitations of satellite missions, the impacts of the revisit cycles and operational periods are quantified. We used 26 observation sets of satellite altimetry over Cumberland River basin that are generated by considering both repeat cycles and satellite operation periods. For the revisit cycles, increasing the interval of repeat cycle leads to a corresponding increase of mean NRMSE from 27 to 59% as a result of sampling fewer flood events and smoothing of the change in storage signal as a result of longer intervals between visits. For the operation periods, the impact of data periods is limited because of the strong seasonal pattern of reservoir operations. Overall, the results suggest that the generalized routing model derived from reservoir stage observations can be used to simulate reservoir operating conditions, which can be used in forecasting hydrologic impacts of land cover or climate change. Copyright © 2014 John Wiley & Sons, Ltd.
Protective effects of ascorbic acid against the genetic and epigenetic alterations induced by 3,5‐dimethylaminophenol in AA8 cells
Authors: Chao Ming‐Wei , Erkekoglu Pınar , Tseng Chia‐Yi , Ye Wenjie , Trudel Laura J. , Skipper Paul L. , Tannenbaum Steven R. , Wogan Gerald N. 
Published: September 2014

AbstractExposure to monocyclic aromatic alkylanilines (MAAs), namely 2,6‐dimethylaniline (2,6‐DMA), 3,5‐dimethylaniline (3,5‐DMA) and 3‐ethylaniline (3‐EA), was significantly and independently associated with bladder cancer incidence. 3,5‐DMAP (3,5‐dimethylaminophenol), a metabolite of 3,5‐DMA, was shown to induce an imbalance in cytotoxicity cellular antioxidant/oxidant status, and DNA damage in mammalian cell lines. This study was designed to evaluate the protective effect of ascorbic acid (Asc) against the cytotoxicity, reactive oxygen species (ROS) production, genotoxicity and epigenetic changes induced by 3,5‐DMAP in AA8 Chinese Hamster Ovary (CHO) cells. In different cellular fractions, 3,5‐DMAP caused alterations in the enzyme activities orchestrating a cellular antioxidant balance, decreases in reduced glutathione levels and a cellular redox ratio as well as increases in lipid peroxidation and protein oxidation. We also suggest that the cellular stress caused by this particular alkylaniline leads to both genetic (Aprt mutagenesis) and epigenetic changes in histones 3 and 4 (H3 and H4). This may further cause molecular events triggering different pathological conditions and eventually cancer. In both cytoplasm and nucleus, Asc provided increases in 3,5‐DMAP‐reduced glutathione levels and cellular redox ratio and decreases in the lipid peroxidation and protein oxidation. Asc was also found to be protective against the genotoxic and epigenetic effects initiated by 3,5‐DMAP. In addition, Asc supplied protection against the cell cycle (G1 phase) arrest induced by this particular alkylaniline metabolite. Copyright © 2014 John Wiley & Sons, Ltd.
Hydrophobic sodium fluoride‐based nanocrystals doped with lanthanide ions: assessment of in vitro toxicity to human blood lymphocytes and phagocytes
Authors: Sojka Bartlomiej , Kuricova Miroslava , Liskova Aurelia , Bartusova Maria , Banski Mateusz , Misiewicz Jan , Dusinska Maria , Horvathova Mira , Jahnova Eva , Ilavska Silvia , Szabova Michaela , Rollerova Eva , Podhorodecki Artur , Tulinska Jana 
Published: September 2014

ABSTRACTIn vitro immunotoxicity of hydrophobic sodium fluoride‐based nanocrystals (NCs) doped with lanthanide ions was examined in this study. Although there is already a significant amount of optical and structural data on NaYF4 NCs, data on safety assessment are missing. Therefore, peripheral whole blood from human volunteers was used to evaluate the effect of 25 and 30 nm hydrophobic NaYF4 NCs dissolved in cyclohexane (CH) on lymphocytes, and of 10 nm NaYF4 NCs on phagocytes. In the concentration range 0.12–75 µg cm−2 (0.17–106 µg ml−1), both 25 and 30nm NaYF4 NCs did not induce cytotoxicity when measured as incorporation of [3H]‐thymidine into DNA. Assessment of lymphocyte function showed significant suppression of the proliferative activity of T‐lymphocytes and T‐dependent B‐cell response in peripheral blood cultures (n = 7) stimulated in vitro with mitogens phytohemagglutinin (PHA) and pokeweed (PWM) (PHA > PWM). No clear dose–response effect was observed. Phagocytic activity and respiratory burst of leukocytes (n = 5–8) were generally less affected. A dose‐dependent suppression of phagocytic activity of granulocytes in cultures treated with 25 nm NCs was observed (vs. medium control). A decrease in phagocytic activity of monocytes was found in cells exposed to higher doses of 10 and 30 nm NCs. The respiratory burst of phagocytes was significantly decreased by exposure to the middle dose of 30 nm NCs only. In conclusion, our results demonstrate immunotoxic effects of hydrophobic NaYF4 NCs doped with lanthanide ions to lymphocytes and to lesser extent to phagocytes. Further research needs to be done, particularly faze transfer of hydrophobic NCs to hydrophilic ones, to eliminate the solvent effect. Copyright © 2014 John Wiley &#38; Sons, Ltd.
Induction of Complementary Function Reductase Enzymes in Colon Cancer Cells by Dithiole‐3‐thione versus Sodium Selenite
Authors: Erzinger Melanie M. , Bovet Cédric , Uzozie Anuli , Sturla Shana J. 
Published: September 2014

ABSTRACTCellular induction of reductase enzymes can alter the susceptibility of cells toward drugs and chemicals. In this study, we compared the capacity of a single dose of sodium selenite and 3H‐1,2‐dithiole‐3‐thione (D3T) to influence the drug‐relevant reducing capacity of HT29 cells over time, and defined the protein‐specific contribution to this activity on the basis of selected reaction monitoring mass spectrometry. Thioredoxin reductase 1 (TrxR1) protein levels and activity were inducible up to 2.2‐fold by selenium. In contrast, selenium had only a minor influence on prostaglandin reductase 1 (PTGR1) and NAD(P)H:quinone oxidoreductase 1 (NQO1) activity and protein levels. D3T, a strong Nrf2 inducer, induced all the reductases and additionally increased the cytotoxicity of hydroxymethylacylfulvene, a bioreductive DNA‐alkylating drug. The data and experimental approaches allow one to define induction potency for reductase enzymes PTGR1, TrxR1, and NQO1 in HT29 cells and link these to changes in drug cytotoxicity.
Clinical Significance of Middle Turbinate Lateralization After Endoscopic Sinus Surgery
Authors: Bassiouni Ahmed , Chen Philip G. , Naidoo Yuresh , Wormald Peter‐John 
Published: September 2014

Objectives/HypothesisTo investigate the clinical significance of middle turbinate lateralization (MTL) occurrence postendoscopic sinus surgery (ESS) for chronic rhinosinusitis, namely, association with postoperative symptoms and eventual need for undergoing revision surgery.Study DesignRetrospective chart review of consecutive postoperative follow‐up appointments (November 2009–May 2011) for patients who had had full‐house ESS (post hoc analysis).MethodsEndoscopic video recordings were reviewed by a blinded reviewer to determine occurrence of MTL (any portion of the middle turbinate touching the lateral nasal wall). Postoperative symptom questionnaires using the Adelaide scoring system were collected. Records were reviewed to determine the need for revision surgeries during follow‐up.ResultsA total of 151 patients had follow‐up with video endoscopy from 2009 to 2011. No statistically significant association between MTL and symptoms was found (P > .05). Of the patients with MTL, 21% required revision versus 9% in those who had no MTL (P = .07). Log‐rank test showed that there was a statistically significant difference between the revision surgery survival curves for the MTL and no‐MTL groups (P = .03). Controlling for the inability to examine the frontal sinus, the difference between the two survival functions increased (P = .005).ConclusionsMTL was not associated with patient‐reported symptoms, but may be associated with a more rapid need for future revision surgery. We hypothesize that this effect is related to interference with the frontal sinus.Level of Evidence4. Laryngoscope, 125:36–41, 2015
Molecular interaction originating from polar functional group in lubricants and its relationship with their traction property under elastohydrodynamic lubrication
Authors: Takiwatari Koji , Nanao Hidetaka , Hoshi Yasushi , Mori Shigeyuki 
Published: September 2014

AbstractThe correlation between molecular interaction and traction properties was investigated using a traction tester and in situ observation of elastohydrodynamic lubrication film with a micro‐Fourier transform infrared spectrometer. The sample oils used were polypropylene glycols (PPGs) with the end‐group of alcohol or ether and a synthetic hydrocarbon oil, poly‐α‐olefin. From the traction tests, it was found that the traction coefficient of PPG was sensitive to the end‐group. PPG with alcohol as the end‐group showed a higher traction coefficient than that with the ether group. In situ observation with a micro‐Fourier transform infrared was performed in order to investigate the molecular interaction of the lubricant oil. It was found that the hydrogen bonding of hydroxyl groups in PPG was strengthened by high pressure in the Hertzian contact region. These results suggest that the rheological properties in the elastohydrodynamic lubrication contact region were affected by the strengthened hydrogen bonding. Copyright © 2014 John Wiley & Sons, Ltd.
Tracer Diffusion in Heterogeneous Polymer Networks
Authors: Di Lorenzo Fany , Seiffert Sebastian 
Published: September 2014

The diffusion of linear polymer chains in swollen polymer networks is studied with different extents of spatial heterogeneity of their crosslinking density. Structural heterogeneity is imparted to these gels by photo‐crosslinking of polymer precursor chains in semidilute solution, which comprise either just one batch of precursors, yielding gels with just a little spatial heterogeneity, or mixtures of two different batches of precursors, one with high and one with low degree of functionalization with crosslinkable moieties, yielding gels with more pronounced heterogeneity. In addition, heterogeneous gels are also prepared from crosslinkable precursor chains and defined fractions of pre‐crosslinked microgel particles that serve as doped‐in nanometer‐scale domains of high local crosslinking density. The resulting gels are probed by static light scattering and shear rheology, and the self‐diffusion of fluorescent linear tracer chains within the gels is studied by fluorescence recovery after photobleaching. The outcome of these investigations is that spatial heterogeneity of a given crosslinking density in swollen polymer networks decreases their ability to store mechanical deformation energy, but has no marked impact on the above‐micrometer‐scale diffusivity of linear tracer chains.image
Breath Figures of Nanoscale Bricks: A Universal Method for Creating Hierarchic Porous Materials from Inorganic Nanoparticles Stabilized with Mussel‐Inspired Copolymers
Authors: Saito Yuta , Shimomura Masatsugu , Yabu Hiroshi 
Published: September 2014

High‐performance catalysts and photovoltaics are required for building an environmentally sustainable society. Because catalytic and photovoltaic reactions occur at the interfaces between reactants and surfaces, the chemical, physical, and structural properties of interfaces have been the focus of much research. To improve the performance of these materials further, inorganic porous materials with hierarchic porous architectures have been fabricated. The breath figure technique allows preparing porous films by using water droplets as templates. In this study, a valuable preparation method for hierarchic porous inorganic materials is shown. Hierarchic porous materials are prepared from surface‐coated inorganic nanoparticles with amphiphilic copolymers having catechol moieties followed by sintering. Micron‐scale pores are prepared by using water droplets as templates, and nanoscale pores are formed between the nanoparticles. The fabrication method allows the preparation of hierarchic porous films from inorganic nanoparticles of various shapes and materials.
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Sleep Attacks in Patients With Parkinson's Disease on Dopaminergic Medications: A Systematic Review
Authors: Yeung Eugene Y.H. , Cavanna Andrea E. 
Published: September 2014

AbstractDopaminergic medications are used as first‐line treatment for Parkinson's disease (PD). In 1999, a case series was published describing 9 patients who took dopamine agonists (pramipexole or ropinirole) and experienced sudden irresistible sleep attacks. Sleep attacks have subsequently been reported with other dopaminergic medications, including levodopa. Because these symptoms might not be rare and can affect health‐related quality of life, we set out to review the prevalence and clinical characteristics of sleep attacks in patients with PD on dopaminergic medications. We conducted a systematic literature review using the terms parkinson* AND dopamine* AND narcolep* OR sleep attack in multiple databases (PubMed, Embase, and PsycINFO). The systematic literature review yielded 23 relevant articles, including nine case reports or case series and 14 original studies. According to the pooled data from the five studies reporting prevalence figures (n = 10,084), sleep attacks occur in 13.0% of patients with PD on dopaminergic medications. Our analysis failed to show significant differences in the Epworth Sleepiness scores between patients with and without sleep attacks (mean difference: 2.92; 95% confidence interval: −0.47–6.31). The I2 value of 76% indicated high heterogeneity among the studies. Sleep attacks are not a rare occurrence in patients with PD on dopamine agonist treatment. We found conflicting results on whether sleep attacks in PD resemble narcolepsy. The pathophysiology of these symptoms might be related to dopamine D2 and D4 receptor gene polymorphisms. The most effective management strategies were dose reduction and discontinuation of the offending drugs.
How Do I Examine Nonmotor Aspects of Parkinson's Disease? What Not to Miss and What to Ignore?
Authors: Todorova Antoniya , Martin Anne , Chaudhuri K. Ray 
Published: September 2014

AbstractNonmotor symptoms (NMS) of Parkinson's disease are a wide range of symptoms that occur well before the onset of the motor syndrome and are present right until the end of life. NMS could be classified to several types and broadly belong to dopaminergic, nondopaminergic, drug‐induced subgroups and those related to motor response fluctuations. NMS are relatively under‐recognized in clinical practice and can be rapidly assessed in the clinic by asking patients to complete the Non‐Motor Symptoms Questionnaire (which can be downloaded from http://www.movementdisorders.org/MDS/Education/Rating-Scales/Rating-Scales-By-Disorder.htm) while they are waiting to be seen. The consultation thereafter can cover the important aspects of the symptoms that have been declared by the patient in addition to the management of the motor symptoms.
Hydrofunktionalisierung mit unüblicher Regioselektivität
Authors: Gulder Tanja , Gulder Tobias A. M. 
Published: September 2014

AbstractDie Photoredoxkatalyse mit sichtbarem Licht ist ein neues Werkzeug, um die übliche Markownikow‐Selektivität bei der Hydrofunktionalisierung umzukehren.
Lernpfade gestalten, analysieren und neue Wege beschreiten
Authors: Pietrusky Stefan , Schuhen Katrin 
Published: September 2014

AbstractDas onlinebasierte Lern‐ und Lehrsystem Crosslinkedlab unterstützt Unterricht und Lehre in der Chemie. Die individuell anpassbare Software hilft Studenten, mit der heutigen Informationsfülle zurecht zu kommen. Eine neue Erweiterung macht unter anderem Reaktionsmechanismen leichter verständlich und vernetzt Theorie und Praxis naturwissenschaftlichen Arbeitens.
Pferd oder Rind?
Authors: von Bargen Christoph , Humpf Hans‐Ulrich , Brockmeyer Jens 
Published: September 2014

AbstractZur Qualitätssicherung bei Lebensmitteln gehört der Nachweis, ob die Angaben des Herstellers über die Inhalte stimmen. Targeted Proteomics liefert bei tierischen Produkten Authentizitätsnachweise: Die neue Methode zeigt an, von welcher Tierart die Proteine in einem Fleischgericht stammen.
Chemische Identität einzelner Partikel
Authors: Huck‐Jones Deborah , Hessemann Renate 
Published: September 2014

AbstractProbleme der Pulvercharakterisierung, bei denen Größe und Form der Partikel alleine nicht genügend Informationen liefern, löst die Kombination aus Bildanalyse und Ramanspektroskopie. Zwei Beispiele sind Drogenfahndung und Zementproduktion.
Der Weg in den Beruf
Authors: Plasa Tim 
Published: September 2014

AbstractChemiker finden schneller eine Stelle als Biologen, verdienen als Berufseinsteiger aber weniger als Chemieingenieure. Dies sind einige der Ergebnisse einer Absolventenbefragung. Nach wie vor gilt Chemikern der Bachelorabschluss nicht als berufsqualifizierend, und die wenigen, die mit dem Bachelor ins Berufsleben starten, fühlen sich oft überfordert.
Key parameters in determining energy generated by CPV modules
Authors: Kurtz Sarah , Muller Matthew , Jordan Dirk , Ghosal Kanchan , Fisher Brent , Verlinden Pierre , Hashimoto Jun , Riley Daniel 
Published: September 2014

AbstractWe identify the key inputs and measurement data needed for accurate energy rating of concentrator photovoltaic (CPV) modules based on field observations of multiple CPV modules. Acceptance angle is shown to correlate with the observed module‐level performance ratio (PR) for the modules studied. Using power ratings based on concentrator standard test conditions, PRs between 90% and 95% were observed during the summers with up to ~10% lower PRs during the winters. A module fabricated by Semprius showed 94% ±0.7% PR over almost 2 years with seasonal variation in PR of less than 1% showing how a module with relatively large acceptance angle may show very consistent average efficiency (calculated from the energy generated relative to the energy available), potentially simplifying energy ratings. The application of the results for translation of energy rating from one location to another is discussed, concluding that most of the translation differences may be correlated with temperature differences between sites with the largest variation happening when optical efficiency depends on temperature. Copyright © 2014 John Wiley & Sons, Ltd.
Physical and structural basis for polymorphism in amyloid fibrils
Authors: Tycko Robert 
Published: September 2014

AbstractAs our understanding of the molecular structures of amyloid fibrils has matured over the past 15 years, it has become clear that, while amyloid fibrils do have well‐defined molecular structures, their molecular structures are not uniquely determined by the amino acid sequences of their constituent peptides and proteins. Self‐propagating molecular‐level polymorphism is a common phenomenon. This article reviews current information about amyloid fibril structures, variations in molecular structures that underlie amyloid polymorphism, and physical considerations that explain the development and persistence of amyloid polymorphism. Much of this information has been obtained through solid state nuclear magnetic resonance measurements. The biological significance of amyloid polymorphism is also discussed briefly. Although this article focuses primarily on studies of fibrils formed by amyloid‐β peptides, the same principles apply to many amyloid‐forming peptides and proteins.