bluuebunny/crossref_metadata_2025_split huggingface dataset:
Short‐Mesochannel SBA‐15‐Supported Chiral 9‐Amino Epicinchonine for Asymmetric Transfer Hydrogenation of Aromatic Ketones
Authors: Lou Lan‐Lan , Li Shanshan , Du Huanling , Zhang Jiong , Yu Wenjun , Yu Kai , Liu Shuangxi 
Published: February 2016

AbstractA short‐mesochannel SBA‐15 material functionalized with propylthiol groups was prepared by co‐condensation and applied to the immobilization of chiral 9‐amino epicinchonine. After complexing with [Ir(cod)Cl]2 (cod=1,5‐cyclooctadiene), these mesoporous materials were evaluated as catalysts for the asymmetric transfer hydrogenation of aromatic ketones. Higher enantioselectivities and comparable, or even higher, catalytic activities were achieved compared with the free catalyst. Both the short mesochannel and co‐condensation approach for short‐mesochannel SBA‐15 materials functionalized with propylthiol groups, [SSBA‐SH(x)] materials were demonstrated to contribute to the excellent catalytic performance. In addition, the catalyst SSBA‐AEC(5)/Ir (AEC=9‐amino epicinchonine), with low 3‐mercaptopropyltrimethoxysilane (MPTMS) content, showed the best catalytic performance; a high enantiomeric excess of 84 % (homogeneous ee=60 %) along with a conversion of 97 % was achieved within 1 h for asymmetric transfer hydrogenation of acetophenone. Moreover, these immobilized catalysts showed high stability during the reaction and could be recovered for reuse.
In Situ FTIR Spectroscopy: Probing the Electrochemical Interface during the Oxygen Reduction Reaction on a Commercial Platinum High‐Surface‐Area Catalyst
Authors: Nesselberger Markus , Arenz Matthias 
Published: February 2016

AbstractIn situ observation of anion adsorption on industrial high‐surface‐area catalysts is used for the first time under oxygen reduction reaction (ORR) conditions with a defined mass transport. For this purpose, a specially fabricated electrode is used for which the catalyst layer is spray‐coated on top of a structured Au contact layer and applied to our recently developed in situ attenuated total reflectance FTIR wall‐jet electrode. The designed interface allows us to track anion adsorption and measure the reaction rate simultaneously under mass controlled conditions. The observed absorption bands are caused by anion interaction with the active phase and also the carbon support. If we analyze the absorption band intensity of adsorbed anions as a function of the oxygen reduction reaction rate, the band intensity decreases with the onset of the ORR. This shows that ORR inhibition is a complex interplay between site blocking caused by anion adsorption and oxide formation.
On the Importance of Regulating Hydroxyl Coverage on the Basal Plane of Graphene Oxide for Supercapacitors
Authors: Pak Alexander J. , Hwang Gyeong S. 
Published: February 2016

AbstractReduced graphene oxide (rGO) has been explored as an alternative to graphene as an electrode material for use in supercapacitors, which thus enables highly scalable solution‐based processing. To understand the performance of rGO electrodes in supercapacitors, we theoretically investigate model systems by considering OH‐functionalized graphene immersed in 1‐ethyl‐3‐methylimidazolium bis(fluorosulfonyl)imide (EMIM/FSI) ionic liquid. Our specific interest is to understand the influence of varying the hydroxyl content (or O/C ratio) on both the quantum (CQ) and electric double‐layer (CD) capacitances. Ultimately, the total interfacial capacitance is found to be sensitive to O/C, but is optimized when the suppression of CD is most effectively mitigated by the enhancement in CQ. Our findings clearly demonstrate that the use of GO materials has the potential to enhance supercapacitor performance significantly but will require careful control of both the concentration and composition of oxygen functional groups along the basal surface.
Aggregation‐Induced Emission Active Probe for Light‐Up Detection of Anionic Surfactants and Wash‐Free Bacterial Imaging
Authors: Gao Meng , Wang Luochao , Chen Junjian , Li Shiwu , Lu Guanhai , Wang Lin , Wang Yingjun , Ren Li , Qin Anjun , Tang Ben Zhong 
Published: February 2016

AbstractAnionic surfactants are widely used in daily life and industries, but their residues can cause serious damage to the environment. The current detection methods for anionic surfactants suffer from various limitations and a new detection strategy is highly desirable. Based on 2‐(2‐hydroxyphenyl)benzothiazole fluorogen with aggregation‐induced emission characteristics, we have developed a fluorescent probe HBT‐C18 for selective and sensitive detection of anionic surfactants. By in situ formation of catanionic aggregates or micelles with anionic surfactants, the emission intensity of the HBT‐C18 probe can increase with increasing keto/enol emission ratio through restriction of intramolecular motion and excited‐state intramolecular proton‐transfer mechanisms. The probe can also be used for wash‐free imaging of bacteria enveloped by a negatively charged outer membrane. The results of this study provide a new strategy for sensitive detection of anionic surfactants and wash‐free bacterial imaging.
Helical Oligoenes: Conformations, Bond Alternation, and Competing Through‐Bond and Through‐Space Transmission
Authors: Tsuji Yuta , Hoffmann Roald 
Published: February 2016

AbstractThere is a consensus that long‐range electron transfer/transport occurs by a through‐bond rather than through‐space mechanism. In helical all‐Z, all‐s‐cis oligoenes, one can set up an interesting competition in the medium‐separation regime between a closer (in distance) through‐space path and a more distant through‐bond one. Although such oligoene conformations/isomers are unstable (by around 4 kcal mol−1 per double bond relative to all‐E, all‐s‐trans isomers), recent synthetic efforts on truncated helicenes and oligothiophenes have provided related molecules. On the way to transmission calculations with electrodes attached to the termini of helical oligoenes, we uncover an interesting conformational ambiguity in all‐Z, all‐s‐cis oligoenes, the existence of a broad conformational minimum for helical compression, with hints of end‐to‐end frontier‐orbital‐caused stabilization. There is relationship between helical oligoene structures and the corresponding substructure of a helicene, but there are also significant differences in the number of olefin subunits per helix turn. In Hückel transport calculations, the role of TB or TS mechanisms is obscured to an extent by variations in bond alternation and dihedral angle along the oligomer chain. However, the operation of a dominant through bond mechanism emerges clearly in local transmission plots. In moving the electrodes to carbon position related by quantum interference, it is possible to uncover a through space mechanism.
Reactivity, Selectivity, and Reaction Mechanisms of Aminoguanidine, Hydralazine, Pyridoxamine, and Carnosine as Sequestering Agents of Reactive Carbonyl Species: A Comparative Study
Authors: Colzani Mara , De Maddis Danilo , Casali Gaia , Carini Marina , Vistoli Giulio , Aldini Giancarlo 
Published: February 2016

AbstractReactive carbonyl species (RCS) are endogenous or exogenous byproducts involved in the pathogenic mechanisms of different oxidative‐based disorders. Detoxification of RCS by carbonyl quenchers is a promising therapeutic strategy. Among the most studied quenchers are aminoguanidine, hydralazine, pyridoxamine, and carnosine; their quenching activity towards four RCS (4‐hydroxy‐trans‐2‐nonenal, methylglyoxal, glyoxal, and malondialdehyde) was herein analyzed and compared. Their ability to prevent protein carbonylation was evaluated in vitro by using an innovative method based on high‐resolution mass spectrometry (HRMS). The reactivity of the compounds was RCS dependent: carnosine efficiently quenched 4‐hydroxy‐trans‐2‐nonenal, pyridoxamine was particularly active towards malondialdehyde, aminoguanidine was active towards methylglyoxal and glyoxal, and hydralazine efficiently quenched all RCS. Reaction products were generated in vitro and were characterized by HRMS. Molecular modeling studies revealed that the reactivity was controlled by specific stereoelectronic parameters that could be used for the rational design of improved carbonyl quenchers.
Convenient, Reliable, Bias‐Free Dynamic Patterning of Multiple Types of Cells into Precisely Defined Micropatterns for Co‐Culture Study
Authors: Dai Wen , Li Wanbo , Ren Kangning , Wu Hongkai 
Published: February 2016

AbstractWe present a simple and flexible mechanical approach for 2D micropatterning of multiple cell lines without surface modification. The principle is that during initial attachment cells only stick to unoccupied areas; we create such areas to selectively seed a subsequent cell line by using a stamp to erase previously attached cells at designed areas. By repeating this process, multiple types of cells were patterned on a single substrate. This strategy minimizes the disturbance to cell health, which might be a concern in printing‐based patterning. Micropatterns of cells with resolution of ≈50 μm, and a co‐culture of three cell types were easily achieved and studied. This method was found universal to at least MSC, HeLa, HepG2 and NIH 3T3. We also measured the invasion and cell growth under the co‐culture of HeLa, MSC and HepG2. This method is useful for studying cell–cell interaction in high‐throughput, free of the potential bias caused by selective surface modification in some previous methods.
High‐Pressure Raman and Calorimetry Studies of Vanadium(III) Alkyl Hydrides for Kubas‐Type Hydrogen Storage
Authors: Morris Leah , Trudeau Michel L. , Reed Daniel , Book David , Antonelli David M. 
Published: February 2016

AbstractThe front cover artwork is provided by David Antonelli′s materials chemistry group at the University of South Wales. The image shows the binding of H2 via the Kubas interaction on amorphous vanadium hydride frameworks. The material stores 5.4 wt % H2 reversibly, and surprisingly the calorimetry measurements shown below the central image demonstrate that the overall process is thermodynamically neutral. Read the full text of the Full Paper at 10.1002/cphc.201501093
A true single‐phase clock dual‐modulus prescaler with enhanced robustness against leakage currents
Authors: Jia Song , Wang Ziyi , Yan Shilin , Wang Yuan 
Published: February 2016

SummaryA new leakage‐tolerant true single‐phase clock dual‐modulus prescaler based on a stage‐merged scheme is presented. Leakage‐restricting transistors are used to reduce the leakage currents at critical nodes, and leakage‐related malfunctions are eliminated at minimal cost in terms of speed, power, and area overheads. An HSPICE simulation in a 40‐nm process shows that the proposed divide‐by‐2/3 divider can effectively enhance robustness against leakage currents to extend the low frequency limit of the circuit over wide temperature and threshold voltage ranges. Additionally, the proposed design shows speed and power performance that is comparable with the performance levels of referenced designs. Copyright © 2016 John Wiley & Sons, Ltd.
Circulating fibroblast growth factor‐23 plasma levels predict adverse cardiovascular outcomes in patients with diabetes mellitus with coronary artery disease
Authors: Tuñón José , Fernández‐Fernández Beatriz , Carda Rocío , Pello Ana M. , Cristóbal Carmen , Tarín Nieves , Aceña Álvaro , González‐Casaus María Luisa , Huelmos Ana , Alonso Joaquín , Lorenzo Óscar , González‐Parra Emilio , Hernández‐González Ignacio , Mahíllo‐Fernández Ignacio , López‐Bescós Lorenzo , Egido Jesús 
Published: February 2016

AbstractBackgroundAbnormalities of fibroblast growth factor‐23 (FGF‐23) plasma levels predict adverse outcomes in patients with coronary artery disease. However, FGF‐23 has a different behaviour in the presence of type 2 diabetes mellitus (T2D). We explored whether the presence of T2D affects the predictive power of FGF‐23.MethodsIn 704 patients with stable coronary artery disease, FGF‐23, calcidiol, parathormone (PTH) and phosphate plasma levels were prospectively assessed. The primary outcome was the development of acute ischemic events (acute coronary syndrome, stroke or transient ischemic attack), heart failure or death.ResultsOne hundred seventy‐three (24.6%) patients had T2D, without differences in age, sex or estimated glomerular filtration rate as compared with non‐diabetic patients. Serum PTH was lower and phosphate higher in T2D than in non‐diabetic patients, without differences in FGF‐23 or calcidiol levels.During follow‐up (2.15 ± 0.99 years), 26 (15.2%) T2D and 51 (9.6%) non‐diabetic patients developed the outcome (p = 0.048). T2D patients who developed the outcome had higher FGF‐23 [112.0 (59.9, 167.6) vs 68.9 (54.2, 93.0) RU/mL; p = 0.002], PTH [71.3 (47.3, 106.6) vs 51.9 (40.8, 66.2) pg/mL; p = 0.004) and phosphate (3.53 ± 0.71 vs 3.25 ± 0.50 mg/dL; p = 0.017) levels than T2D subjects who remained stable. These differences were not significant in non‐diabetic patients.By multivariable Cox proportional hazard model, FGF‐23 predicted independently the outcome in T2D patients [hazard ratio = 1.277; 95% CI (1.132, 1.442)] but not in those without T2D.ConclusionsFGF‐23 plasma levels predict adverse cardiovascular outcomes in coronary artery disease patients who have T2D but not in those without T2D. This finding should be confirmed in larger studies. Copyright © 2016 John Wiley & Sons, Ltd.
Prediabetes and diabetes among HIV‐infected adults in Cameroon
Authors: Rhee John Y. , Bahtila Tumi Divine , Palmer Dennis , Tih Pius Muffih , Aberg Judith A. , LeRoith Derek , Jao Jennifer 
Published: February 2016

AbstractBackgroundHuman immunodeficiency virus (HIV) and certain antiretrovirals are associated with diabetes. Few studies have examined the prevalence of and factors associated with diabetes among HIV‐infected individuals on combination antiretroviral therapy (cART) in sub‐Saharan Africa; some report prevalence estimates between 3.5–26.5% for diabetes in Cameroon and 20.2–43.5% for prediabetes in sub‐Saharan Africa.MethodsIn a cross‐sectional study, HIV‐infected individuals (16–65 years old) were screened for diabetes using haemoglobin A1c (HbA1c). We further categorized HbA1C as normoglycemia (HbA1c < 5.7%), prediabetes (HbA1c 5.7–6.4%) or diabetes (HbA1c  ≥ 6.5%). Dysglycemia was defined as HbA1c ≥ 5.7%. Logistic regression modelling was used to assess factors associated with having dysglycemia.ResultsOf 500 participants, 363 (72.6%) were female. Median age was 42.5 years [interquartile range (IQR): 36.5–49.5]. Nineteen patients (3.8%) had diabetes and 170 patients (34%) were classified as having prediabetes. One hundred nine (22%) had a CD4+ count <200 cells/mm3, and 464 (93%) had received >28 days of ART at time of screening. Median abdominal circumference for women was 79.5 cm (IQR: 75.5–85.3) and for men, 86.5 cm (IQR: 81.7–90.5). Adjusting for age, sex, socio‐economic status, CD4 cell count, being on cART >28 days, body mass index, hypertension, history of hypertension, abdominal circumference and duration of HIV infection, larger abdominal circumference was associated with higher prevalence of prediabetes or diabetes (adjusted odds ratio = 1.07, 95% confidence interval: 1.03–1.11), while being on cART (adjusted odds ratio = 0.46, confidence interval: 0.22–0.99) was associated with lower prevalence.ConclusionsThere was a high prevalence of dysglycemia among Cameroonian HIV‐infected adults. Larger abdominal circumference was associated with higher prevalence, while cART was associated with lower prevalence. Copyright © 2016 John Wiley & Sons, Ltd.
Selective association of electrocardiographic abnormalities with insulin sensitivity and beta‐cell function in type 2 diabetes mellitus: a cross‐sectional analysis
Authors: Bhatt Anish B. , Mulvey Claire K. , Qasim Atif N. , Nair Jayamohan V. , Rickels Michael R. , Prenner Stuart B. , Iqbal Nayyar , Reilly Muredach P. 
Published: February 2016

AbstractBackgroundWe investigated the association of electrocardiographic (ECG) abnormalities with markers of insulin resistance and pancreatic beta‐cell dysfunction in a cross‐sectional study of type 2 diabetes patients.MethodsElectrocardiographic criteria were evaluated in the Penn Diabetes Heart Study participants (n = 1671; 64% male; 61% Caucasian), including a sub‐sample (n = 710) that underwent oral glucose tolerance testing. The Matsuda Insulin Sensitivity Index and homeostasis model assessment of insulin resistance (HOMA‐IR) estimated insulin sensitivity; Insulinogenic Index and homeostasis model assessment of beta‐cell function assessed beta‐cell function. Multivariable regression modelling was used to analyse associations of ECG changes with these indices.ResultsIn unadjusted analyses, subjects in the highest quartile of Matsuda index had the lowest prevalence of Q‐waves (6.3% versus 15.3%, p = 0.005). In adjusted models, an inverse association was seen between Q‐waves and log Matsuda index [one standard deviation increase; OR = 0.59 (95% CI 0.43‐0.87 p = 0.001)]. In the full Penn Diabetes Heart Study, there was a direct association between Q‐waves and HOMA‐IR [one standard deviation increase; OR = 1.43 (95% CI 1.13–1.81, p = 0.003)]. In adjusted models, left ventricular hypertrophy also was inversely associated with Matsuda index and directly with HOMA‐IR. Higher Insulinogenic Index scores were associated with a lower prevalence of nonspecific ST changes [OR = 0.78 (95% CI 0.62–0.98, p = 0.032)].ConclusionsIn type 2 diabetic patients, both oral glucose tolerance testing‐derived and HOMA‐derived measures of insulin resistance were associated with pathologic Q‐waves and left ventricular hypertrophy on ECGs. Copyright © 2016 John Wiley & Sons, Ltd.
Costs of resistance and infection by a generalist pathogen
Authors: Dallas Tad , Holtackers Mathieu , Drake John M. 
Published: February 2016

AbstractPathogen infection is typically costly to hosts, resulting in reduced fitness. However, pathogen exposure may also come at a cost even if the host does not become infected. These fitness reductions, referred to as “resistance costs”, are inducible physiological costs expressed as a result of a trade‐off between resistance to a pathogen and aspects of host fitness (e.g., reproduction). Here, we examine resistance and infection costs of a generalist fungal pathogen (Metschnikowia bicuspidata) capable of infecting a number of host species. Costs were quantified as reductions in host lifespan, total reproduction, and mean clutch size as a function of pathogen exposure (resistance cost) or infection (infection cost). We provide empirical support for infection costs and modest support for resistance costs for fiveDaphniahost species. Specifically, only one host species examined incurred a significant cost of resistance. This species was the least susceptible to infection, suggesting the possibility that host susceptibility to infection is associated with the detectability and size of resistance cost. Host age at the time of pathogen exposure did not influence the magnitude of resistance or infection cost. Lastly, resistant hosts had fitness values intermediate between unexposed control hosts and infected hosts. Although not statistically significant, this could suggest that pathogen exposure does come at some marginal cost. Taken together, our findings suggest that infection is costly, resistance costs may simply be difficult to detect, and the magnitude of resistance cost may vary among host species as a result of host life history or susceptibility.
Scorched mussels (Brachidontesspp., Bivalvia: Mytilidae) from the tropical and warm‐temperate southwestern Atlantic: the role of the Amazon River in their speciation
Authors: Trovant Berenice , Basso Néstor G. , Orensanz José María , Lessa Enrique P. , Dincao Fernando , Ruzzante Daniel E. 
Published: February 2016

AbstractAntitropicality is a distribution pattern where closely related taxa are separated by an intertropical latitudinal gap. Two potential examples includeBrachidontes darwinianus(south eastern Brazil to Uruguay), considered by some authors as a synonym ofB. exustus(Gulf of Mexico and the Caribbean), andB. solisianus, distributed along the Brazilian coast with dubious records north of the intertropical zone. Using two nuclear (18S and 28SrDNA) and one mitochondrial gene (mtDNA COI), we aimed to elucidate the phylogeographic and phylogenetic relationships among the scorched mussels present in the warm‐temperate region of the southwest Atlantic. We evaluated a divergence process mediated by the tropical zone over alternative phylogeographic hypotheses.Brachidontes solisianuswas closely related toB. exustus I,a species with which it exhibits an antitropical distribution. Their divergence time was approximately 2.6 Ma, consistent with the intensification of Amazon River flow.Brachidontes darwinianus,an estuarine species is shown here not to be related to thisB. exustuscomplex. We suspect ancestral forms may have dispersed from the Caribbean to the Atlantic coast via the Trans‐Amazonian seaway (Miocene). The third species, B rodrigueziiis presumed to have a long history in the region with related fossil forms going back to the Miocene. Although scorched mussels are very similar in appearance, their evolutionary histories are very different, involving major historical contingencies as the formation of the Amazon River, the Panama Isthmus, and the last marine transgression.
Method of Shortening Settling Time Using Final State Control for High‐Precision Stage with Decouplable Structure of Fine and Coarse Parts
Authors: YAZAKI YUMA , FUJIMOTO HIROSHI , HORI YOICHI , SAKATA KOICHI , HARA ATSUSHI , SAIKI KAZUAKI 
Published: February 2016

SUMMARYHigh‐precision stages require high‐speed and high‐precision control to improve their production throughput and quality. However, their motion speed and accuracy are expected to reach a limit in the near future if the conventional high‐precision stage structure is used. Therefore, the authors designed and fabricated a “catapult stage,” which has a structure that can be decoupled into a fine stage and coarse stage. The catapult stage is different from conventional dual stages in which the fine stage is disturbed by the coarse stage because they contact each other. This paper proposes a novel control system design for the catapult stage and a control method that shortens the settling time by using final state control (FSC). So far, FSC has mainly been used for applications such as hard disk drives, for which the initial states are zero. However, it is important to consider the initial states for the catapult stage because the initial position, velocity, and acceleration of the catapult stage are not equal to zero. Simulations and experiments were performed to demonstrate the effectiveness of the proposed methods.