bluuebunny/crossref_metadata_2025 huggingface dataset:
Which psychological, social and physical environmental characteristics predict changes in physical activity and sedentary behaviors during early retirement? A longitudinal study
Authors: Van Dyck Delfien , Cardon Greet , De Bourdeaudhuij Ilse
Published: May 2017

Background

In the context of healthy ageing, it is necessary to identify opportunities to implement health interventions in order to develop an active lifestyle with sufficient physical activity and limited sedentary time in middle-aged and older adults. The transition to retirement is such an opportunity, as individuals tend to establish new routines at the start of retirement. Before health interventions can be developed, the psychological, social and physical environmental determinants of physical activity and sedentary behaviors during early retirement should be identified, ideally with longitudinal studies. The aim of this paper was first to examine whether psychological, social and physical environmental factors at the start of retirement predict longitudinal changes in physical activity and sedentary behaviors during the first years of retirement. Second, moderating effects of gender and educational levels were examined.

Methods

This longitudinal study was conducted in Flanders, Belgium. In total, 180 recently retired (>1 month, <2 years at baseline) adults completed a postal questionnaire twice (in 2012–2013 and two years later in 2014–2015). The validated questionnaire assessed socio-demographic information, physical activity, sedentary behaviors, and psychological, social and physical environmental characteristics. Multiple moderated hierarchic regression analyses were conducted in SPSS 22.0.

Results

Higher perceived residential density (p < 0.001) and lower aesthetics (p = 0.08) predicted an increase in active transportation (adjusted R2 = 0.18). Higher baseline self-efficacy was associated with an increase in leisure-time physical activity (p = 0.001, adjusted R2 = 0.13). A more positive perception of old age (p = 0.04) and perceiving less street connectivity (p = 0.001) were associated with an increase in screen time (adjusted R2 = 0.06). Finally, higher baseline levels of modeling from friends (p = 0.06) and lower perceived land use mix access (p = 0.09) predicted an increase in car use (adjusted R2 = 0.06). A few moderating effects, mainly of educational level, were found.

Discussion

Walkability characteristics (perceived residential density) and self-efficacy at the start of retirement are the most important predictors of longitudinal changes in active transportation and leisure-time physical activity. Few moderating effects were found, so health interventions at the start of retirement focusing on self-efficacy and specific walkability characteristics could be effective to increase physical activity in recently retired adults. No firm conclusions can be drawn on the importance of the examined predictors to explain change in car use and screen time, possibly other factors like the home environment, or automatic processes and habit strength are more important to explain sedentary behaviors.
Radix Stellariae extract prevents high-fat-diet-induced obesity in C57BL/6 mice by accelerating energy metabolism
Authors: Li Yin , Liu Xin , Fan Yu , Yang Baican , Huang Cheng
Published: May 2017

Stellaria dichotoma L.is widely distributed in Ningxia and surrounding areas in northwestern China. Its root, Radix Stellariae (RS), has been used in herbal formulae for treating asthenic-fever, infection, malaria, dyspepsia in children and several other symptoms. This study investigated whether the RS extract (RSE) alleviates metabolic disorders. The results indicated that RSE significantly inhibited body weight gain in high-fat (HF)-diet-fed C57BL/6 mice, reduced fasting glucose levels, and improved insulin tolerance. Moreover, RSE increased the body temperature of the mice and the expression of uncoupling proteins and peroxisome proliferator-activated receptors in the white adipose tissue. Thus, RSE alleviated metabolic disorders in HF-diet-fed C57BL/6 mice by potentially activating UCP and PPAR signaling.
Interaction between turbulent flow and sea breeze front over urban‐like coast in large‐eddy simulation
Authors: Jiang Ping , Wen Zhiping , Sha Weiming , Chen Guixing
Published: May 2017

Turbulent flow and its interaction with a sea breeze front (SBF) over an urban‐like coast with a regular block array were investigated using a building‐resolving computational fluid dynamics model. It was found that during daytime with an offshore ambient flow, streaky turbulent structures tended to grow within the convective boundary layer (CBL) over a warm urban surface ahead of the SBF. The structures were organized as streamwise streaks at an interval of a few hundred meters, which initiated at the rooftop level with strong wind shear and strengthens in the CBL with moderate buoyancy. The streaks then interacted with the onshore‐propagating SBF as it made landfall. The SBF, which was initially characterized as a shallow and quasi‐linear feature over the sea, developed three‐dimensional structures with intensified updrafts at an elevated frontal head after landfall. Frontal updrafts were locally enhanced at intersections where the streaks merged with the SBF, which greatly increased turbulent fluxes at the front. The frontal line was irregular because of merging, tilting, and transformation effects of vorticity associated with streaky structures. Inland penetration of the SBF was slowed by the frictional effect of urban‐like surfaces and turbulent flow on land. The overall SBF intensity weakened after the interaction with turbulent flow. These findings aid understanding of local weather over coastal cities during typical sea breeze conditions.
Cumulative Sum (CUSUM) Chart
Authors: Gan Fah Fatt
Published: May 2017

The use of the cumulative sum (CUSUM) charting procedure in process monitoring is first described. The relationship between the CUSUM charting procedure and Wald's sequential probability ratio test is then explained. This is followed by three main approaches of determining the average run length. The strengths and weaknesses of the CUSUM charting procedure, with respect to the Shewhart charting procedure, are illustrated with simulated data sets. Various other aspects of the CUSUM chart are also discussed. These include estimation of process mean using the CUSUM, weighting of samples for signaling, fast initial response for a newly start‐up process, simultaneous CUSUM schemes, design of CUSUM chart, multivariate CUSUM schemes, and risk‐adjusted CUSUM charts.
Correction Methods for Non‐
G
aussian
B
erkson Errors in Bioassay
Authors: Donev Alexander N.
Published: May 2017

Setting the factor levels in designed experiments is sometimes done with errors. The case when these are Berkson errors is discussed. Ignoring them in the statistical analysis induces inaccurate estimates of the variance of the response of interest and may lead to bias in the estimates of the model parameters. Minimizing this effect can be achieved using correction methods, such as regression calibration and a simulation and extrapolation method. These methods are described and contrasted with the methods used for correcting errors in variables in observation studies. The setting of bioassay experiments is used to illustrate the ideas.

The B‐SIMEX method is particularly effective when the Berkson errors are non‐Gaussian and dependent. Regression calibration is also useful when the errors are independent.
Polysaccharide Nanobiotechnology: A Case Study of Dental Implant Coating
Authors: Morra Marco , Cassinelli Clara , Cascardo Giovanna , Kokkonen Hanna , Tuukkanen Juha , Volpe Claudio Della , Siboni Stefano , Segatta Giordano , Brugnara Marco , Ceccone Giacomo
Published: May 2017

Surface modification of biomaterials and medical devices by polysaccharides is presently a topic of great interest, both at fundamental and applied levels. Plant polysaccharides constitute an untapped resource in this regard. The very self‐assembly properties of the polymers that the plant cell exploits during cell wall biogenesis may be exploited in assembly of contiguous coatings of medical devices and implants. Cell wall polysaccharides not only display advantageous physical properties but some are also known to be biologically active in a mammalian context. Bioactivities include anti‐inflammatory and immunomodulatory effects that are hypothesized to suppress rejection and promote implant integration. These activities are in most cases associated with polysaccharides of the pectin family. The present study thus focuses on engineering biocompatible surfaces using rhamnogalacturonan‐I. The target application is titanium dental implants and the study reports extensively on the methods used for surface characterization, both biological methods that probe biocompatability and nanotechnology methods used for the physical characterization of the modified surfaces.
Nitrogen Assimilation and its Relevance to Crop Improvement
Authors: Lea Peter J. , Miflin Ben J.
Published: May 2017

The majority if not all of the organic nitrogen in plants is derived from the assimilation of ammonia into the amide position of glutamine by the enzyme glutamine synthetase (GS). A second enzyme, glutamate synthase, also known as glutamine:2‐oxoglutarate amidotransferase (GOGAT), carries out the transfer of the amide group of glutamine to 2‐oxoglutarate to yield two molecules of glutamate and thus completes the assimilation of ammonia into amino acids. This GS/GOGAT pathway of ammonia assimilation is of crucial importance for crop growth and productivity and ultimately animal and human nutrition. Glutamate dehydrogenase (GDH) is now considered to be only involved in glutamate catabolism to form ammonia, an important role in N recycling within the plant. Nitrogen is also often diverted from glutamine to asparagine as a temporary measure during periods of carbohydrate shortage and excess of reduced nitrogen. This diversion requires the action of asparagine synthetase in the anabolic reaction and asparaginase in the catabolic reaction. This chapter describes the properties of these enzymes in the assimilation and reassimilation of nitrogen and in particular the genes that encode them, their complexity and the time and place they are expressed. Plant transformation has allowed the construction of a range of plants with enhanced and decreased activity of several of these enzymes, some of which have shown improved agronomic performance.
Transcriptional Profiling Approaches for Studying Nitrogen Use Efficiency
Authors: Hawkesford Malcolm J. , Howarth Jonathan R.
Published: May 2017

Nitrogen use efficiency comprises multiple interacting subtraits. In agronomic terms, the two major components are nitrogen uptake efficiency and nitrogen utilization efficiency, the former dominated by root acquisition processes and the latter describing harvestable yield as function of the nitrogen taken up. The complexity of both of these processes is ideally tackled using genomic approaches including transcriptomics. Profiling gene expression in relation to nitrogen supply and with the consideration of germplasm variation is a route to identifying genes underpinning key traits involved in the efficient use of nitrogen. Substantial progress has been made on identifying nitrogen‐responsive genes in model plant systems; however, a challenge remains to incorporate these technologies into crop improvement programmes. An approach is detailed where field agronomic performance is related to specific gene expression in canopy tissues, which is indicative of the efficiency of nitrogen remobilization processes from the canopy to the grain in wheat. Identified genes include transcription factors likely to be involved in controlling expression of multiple genes encoding the various components in the complex pathways contributing to the traits.
Nitric Oxide Signalling in Plants: Cross‐Talk withCa2+, Protein Kinases and Reactive Oxygen Species
Authors: Astier Jéremy , Besson‐Bard Angélique , Wawer Izabela , Parent Claire , Rasul Sumaira , Jeandroz Sylvain , Dat James , Wendehenne David
Published: May 2017

Nitric oxide (NO) is a gaseous free radical recognized as a ubiquitous signal transducer that contributes to various biological processes in animals. It exerts most of its effects by regulating the activities of various proteins including Ca2+channels, protein kinases and transcription factors. In plants, studies conducted over the past 10 years revealed that NO also functions as an endogenous mediator in diverse physiological processes ranging from root development to stomatal closure. Its biological role as an intracellular plant messenger molecule, however, remains poorly understood. Here, we review the molecular basis of NO signalling in animals and discuss current knowledge of NO signalling in plants, focusing on its interplay with Ca2+, protein kinases and reactive oxygen species which are well established as widespread key regulators of signal transduction.
Crops and Tasty, Nutritious Food – How Can Metabolomics Help?
Authors: Stewart Derek , Shepherd Louise V.T. , Hall Robert D. , Fraser Paul D.
Published: May 2017

Food quality, security and safety have become topics of considerable recent interest. With a rapidly growing world population, entailing an ever‐expanding requirement for food, and with the global consumer making higher and better‐informed demands on our crop and food producers, much attention is being given to how we can meet all these growing needs. Crop growers and food processors alike are already looking at state‐of‐the‐art technologies such as metabolomics as a source of new inroads into the generation of detailed knowledge on the biochemical composition of crop products and how they change during transport, storage and industrial processing. All the steps in the food production chain, from the moment the plant breeder makes the first cross to the canning factory delivering to the supermarket distributor, have potentially significant influence on the quality of the final product the consumer places on the kitchen table. Metabolomics of crop plants and plant products is already being widely applied and is generating new information on the complexity of food composition. In this chapter, some of the main subjects of recent research, concerning both fresh and processed materials, are covered. Emphasis has been laid on technological advances and how we approach food improvement strategies as well as the role of metabolomics is also finding a role in food safety analysis.
Genetics, Genomics and Metabolomics
Authors: Fernie Alisdair R. , Keurentjes Joost J.B.
Published: May 2017

Metabolomics approaches enable the parallel assessment of the levels of a broad range of metabolites. They have been documented to have great value in phenotyping and diagnostic analyses in plants as well as showing great promise as a tool for bio‐prospecting novel pharmaceuticals. These tools have recently been turned to evaluation of the natural variance apparent in metabolite composition both in the model species
Arabidopsis thaliana
and a range of crop species. Here, we describe exciting progress made in the identification of the genetic determinants of plant chemical composition, focusing on the application of various different metabolomics strategies. We focus on the integration of these data with those other high‐throughput technologies and discuss the value of such approaches for gaining fundamental insights into metabolic and even cellular regulation. Finally, we discuss the fact that when considered from an applied perspective metabolomics represents an important addition to the tools currently employed in genomics‐assisted selection for crop improvement.
In Vivo Self‐Powered Wireless Transmission Using Biocompatible Flexible Energy Harvesters
Authors: Kim Dong Hyun , Shin Hong Ju , Lee Hyunseung , Jeong Chang Kyu , Park Hyewon , Hwang Geon‐Tae , Lee Ho‐Yong , Joe Daniel J. , Han Jae Hyun , Lee Seung Hyun , Kim Jaeha , Joung Boyoung , Lee Keon Jae
Published: May 2017

Additional surgeries for implantable biomedical devices are inevitable to replace discharged batteries, but repeated surgeries can be a risk to patients, causing bleeding, inflammation, and infection. Therefore, developing self‐powered implantable devices is essential to reduce the patient's physical/psychological pain and financial burden. Although wireless communication plays a critical role in implantable biomedical devices that contain the function of data transmitting, it has never been integrated with in vivo piezoelectric self‐powered system due to its high‐level power consumption (microwatt‐scale). Here, wireless communication, which is essential for a ubiquitous healthcare system, is successfully driven with in vivo energy harvesting enabled by high‐performance single‐crystalline (1 − x)Pb(Mg1/3Nb2/3)O3−(x)Pb(Zr,Ti)O3 (PMN‐PZT). The PMN‐PZT energy harvester generates an open‐circuit voltage of 17.8 V and a short‐circuit current of 1.74 µA from porcine heartbeats, which are greater by a factor of 4.45 and 17.5 than those of previously reported in vivo piezoelectric energy harvesting. The energy harvester exhibits excellent biocompatibility, which implies the possibility for applying the device to biomedical applications.
Self‐Doping Cathode Interfacial Material Simultaneously Enabling High Electron Mobility and Powerful Work Function Tunability for High‐Efficiency All‐Solution‐Processed Polymer Light‐Emitting Diodes
Authors: Yin Xiaojun , Xie Guohua , Peng Yuhao , Wang Bowen , Chen Tianhao , Li Shuqi , Zhang Wenhao , Wang Lei , Yang Chuluo
Published: May 2017

A variety of N‐hydrogenated/N‐methylated pyridinium salts are elaborately designed and synthesized. Thermogravimetric and X‐ray photoelectron spectra analysis indicate the intensities of the NH covalent bonds are strengthened step‐by‐step from 3,3′‐(5′‐(3‐(pyridin‐3‐yl)phenyl)‐[1,1′:3′,1″‐terphenyl]‐3,3″‐diyl)dipyridine (Tm)‐HCl to Tm‐HBr and then Tm‐TfOH, which results in gradually improved cathode interfacial modification abilities. The larger dipole moments of N+H containing moieties compared to those of the N+CH3 endow them with more preferable interfacial modification abilities. Electron paramagnetic resonance signals reveal the existence of radical anions in the solid state of Tm‐TfOH, which enables its self‐doping property and high electron mobility up to 1.67 × 10−3 cm2 V−1 s−1. Using the Tm‐TfOH as the cathode interfacial layers (CILs), the phenyl‐substituted poly(para‐phenylene vinylene)‐based all‐solution‐processed polymer light‐emitting diodes (PLEDs) achieve more preferable device performances than the poly[(9,9‐bis(3′‐(N,N‐dimethylamino)propyl)‐2,7‐fluorene)‐alt‐2,7‐(9,9‐dioctylfluorene)]‐based ones, i.e., high current density of nearly 300 mA cm−2, very high luminance over 15 000 cd m−2 at a low bias of 5 V. Remarkably, the thickness of the CILs has little impact on the device performance and high efficiencies are maintained even at thicknesses up to 85 nm, which is barely realized in PLEDs with small‐molecule‐based electron transporting layers.
Transmetalation of Alkylzirconocenes in Copper‐Catalyzed Alkyl–Alkynyl Cross‐Coupling Reactions
Authors: Indukuri Kiran , Riant Olivier
Published: May 2017

A simple copper‐catalyzed alkyl–alkynyl cross‐coupling strategy has been developed using the reaction between alkynyl bromides and alkylzirconocenes. The alkylzirconocenes were generated in situ via regioselective addition of Schwartz's reagent (ZrCp2HCl) on to alkenes. The reaction has a broad scope, a range of functionalized bromoalkynes and alkylzirconium reagents were successfully coupled, resulting in moderate to good yields of the desired internal alkynes.

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Polarization‐Dependent Electronic Transport in Graphene/Pb(Zr,Ti)O3 Ferroelectric Field‐Effect Transistors
Authors: Lipatov Alexey , Fursina Alexandra , Vo Timothy H. , Sharma Pankaj , Gruverman Alexei , Sinitskii Alexander
Published: May 2017

Ferroelectric field‐effect transistors (FeFETs) employing graphene on inorganic perovskite substrates receive considerable attention due to their interesting electronic and memory properties. They are known to exhibit an unusual hysteresis of electronic transport that is not consistent with the ferroelectric polarization hysteresis and is previously shown to be associated with charge trapping at graphene–ferroelectric interface. Here, an electrical measurement scheme that minimizes the effect of charge traps and reveals the polarization‐dependent hysteresis of electronic transport in graphene–Pb(Zr,Ti)O3 FeFETs is demonstrated. Observation of the polarization‐dependent conductivity hysteresis is important for the fundamental understanding of the interplay between the ferroelectric polarization and charge carriers in graphene. It is also important for practical memory applications because this hysteresis emulates the operation of nonvolatile memories and reveals the range of ON and OFF currents that can be achieved in long term data storage. It is demonstrated that this measurement scheme can be used to optimize the memory performance of graphene–PZT FeFETs that can exhibit nonvolatile time‐independent ON/OFF ratios of over 5. The described measurement technique can potentially be used in the studies of kinetics of charge trap dissipation, polarization‐dependent properties, and memory performance of FeFET devices comprising other 2D materials and various ferroelectric substrates.
High‐Performance Broadband Perovskite Photodetectors Based on CH3NH3PbI3/C8BTBT Heterojunction
Authors: Tong Sichao , Sun Jia , Wang Chunhua , Huang Yulan , Zhang Chujun , Shen Jianqiang , Xie Haipeng , Niu Dongmei , Xiao Si , Yuan Yongbo , He Jun , Yang Junliang , Gao Yongli
Published: May 2017

Perovskite photodetectors are fabricated via structuring a perovskite/organic heterojunction with CH3NH3PbI3 and a high‐mobility and stable organic semiconductor dioctylbenzothieno [2,3‐b] benzothiophene (C8BTBT), which possess broad range photoresponse from ultraviolet to near‐infrared, fast response, and excellent stability. The CH3NH3PbI3/C8BTBT heterojunction photodetectors exhibit an excellent ratio of photocurrent to dark current, Ilight/Idark, as high as 2.4 × 104, a high responsivity up to 24.8 AW−1, and a fast response of about 4.0 ms. Meanwhile, the photodetectors can maintain 90% performance even exposed in ambient condition without encapsulation for 20 d. In addition, the detailed mechanism is disclosed based on ultraviolet photoemission spectroscopy, steady‐state photoluminescence (PL) spectra, and PL lifetime experiments. The C8BTBT layer acts as an efficient hole‐extraction layer to let the holes quickly transport to the electrodes due to its perfect filling in the gaps between perovskite grains, as well as its intrinsic high mobility and the energy‐level match with the CH3NH3PbI3. The stable C8BTBT layer can well play as a waterproof layer as well to prevent the perovskite CH3NH3PbI3 from the degradation. The research provides an excellent method for fabricating high‐performance and stable perovskite photodetectors using perovskite/organic heterojunction.
Estimates of total body iron indicate 19 mg and 38 mg oral iron are equivalent for the mitigation of iron deficiency in individuals experiencing repeated phlebotomy
Authors: Bialkowski Walter , Kiss Joseph E. , Wright David J. , Cable Ritchard , Birch Rebecca , D'Andrea Pam , Bryant Barbara J. , Spencer Bryan R. , Mast Alan E.
Published: May 2017

Iron deficiency anemia is a common clinical condition often treated with tablets containing 65 mg of elemental iron. Such doses can elicit gastrointestinal side effects lowering patient compliance. Oral iron supplements also increase hepcidin production causing decreased fractional absorption of subsequent doses. Frequent blood donors often become iron deficient. Therefore, they were enrolled in a two‐year study involving continued blood donations and randomization to receive no pill, placebo, 19, or 38 mg ferrous gluconate for 60 days. Total body iron (TBI) did not change for the subset of donors in the no pill and placebo groups who completed both enrollment and final visits (P = .21 and P = .28, respectively). However, repeated measures regression analysis on the complete dataset estimated a significant decrease in TBI of 52 mg/year for the placebo and no pill groups (P = .001). The effects of 19 and 38 mg iron supplementation on TBI were indistinguishable (P = .54). TBI increased by 229 mg after the initial 60 days of iron supplementation (P < .0001) and was maintained at this higher level with continued iron supplementation following each subsequent donation. The TBI increase was apportioned 51 mg to red cell iron (P < .0001) and 174 mg to storage iron (P < .0001). Changes in storage iron were negatively impacted by 57 mg due to concurrent antacid use (P = .04). These findings in blood donors suggest that much lower doses of iron than are currently used will be effective for clinical treatment of iron deficiency anemia.
Dielectric response of frustrated water down to a single‐molecule contribution
Authors: Fernández Ariel
Published: May 2017

A theory of dielectric response of water under nanoscale confinement was long overdue. This work addresses the problem by establishing a relation between dielectric response and hydrogen‐bond frustration subsumed in a non‐Debye polarization term. The results hold down to the single‐molecule contribution and are validated vis‐à‐vis experimental measurements on a system where dielectric modulation entails removal of a single water molecule. The frustrated dielectric response down to molecular scales is assessed by contrasting two enantiomeric ligands in association with the same protein, with the complexes differing in the removal of a single interfacial water molecule.

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Detection of Localized Hepatocellular Amino Acid Kinetics by using Mass Spectrometry Imaging of Stable Isotopes
Authors: Arts Martijn , Soons Zita , Ellis Shane R. , Pierzchalski Keely A. , Balluff Benjamin , Eijkel Gert B. , Dubois Ludwig J. , Lieuwes Natasja G. , Agten Stijn M. , Hackeng Tilman M. , van Loon Luc J. C. , Heeren Ron M. A. , Olde Damink Steven W. M.
Published: May 2017

Mass spectrometry imaging (MSI) simultaneously detects and identifies the spatial distribution of numerous molecules throughout tissues. Currently, MSI is limited to providing a static and ex vivo snapshot of highly dynamic systems in which molecules are constantly synthesized and consumed. Herein, we demonstrate an innovative MSI methodology to study dynamic molecular changes of amino acids within biological tissues by measuring the dilution and conversion of stable isotopes in a mouse model. We evaluate the method specifically on hepatocellular metabolism of the essential amino acid l‐phenylalanine, associated with liver diseases. Crucially, the method reveals the localized dynamics of l‐phenylalanine metabolism, including its in vivo hydroxylation to l‐tyrosine and co‐localization with other liver metabolites in a time course of samples from different animals. This method thus enables the dynamics of localized biochemical synthesis to be studied directly from biological tissues.
Access to Hexahydrocarbazoles: The Thorpe–Ingold Effects of the Ligand on Enantioselectivity
Authors: Chen Hao , Wang Lijia , Wang Feng , Zhao Liu‐Peng , Wang Pan , Tang Yong
Published: May 2017

A novel cyclization reaction of methylenemalonate with indoles is reported, and it provides efficient access to a variety of hexahydrocarbazoles. The enantioselective version was realized by a finely tuned ligand/CuII catalyst. The optically active hexahydrocarbazoles contain three quaternary carbon centers and are obtained in up to 99 % yield with greater than 99:1 d.r. and up to greater than 99 % ee. This reaction can be carried out on gram scale and stereoselective transformation of the product led to the core structure of a series of alkaloids from Kopsia plants.
Silver‐Catalyzed Three‐Component 1,1‐Aminoacylation of Homopropargylamines: α‐Additions for Both Terminal Alkynes and Isocyanides
Authors: Tong Shuo , Piemontesi Cyril , Wang Qian , Wang Mei‐Xiang , Zhu Jieping
Published: May 2017

The reaction of secondary homopropargylamines, isocyanides, and water in the presence of a catalytic amount of silver acetate and subsequent purification by chromatography on silica gel afforded substituted proline amides in good to excellent yields. Primary homopropargylamines underwent a cyclizative Ugi–Joullié three‐component reaction with isocyanides and carboxylic acids to afford functionalized N‐acyl proline amides. High diastereoselectivity was observed in the synthesis of 4‐alkoxy and 4,5‐disubstituted proline derivatives. This work represents the first examples of a three‐component cyclizative 1,1‐aminoacylation of terminal alkynes.
Structure–stability correlation of copolyimide membranes derived from aliphatic/alicyclic/aromatic diamine and aromatic dianhydrides
Authors: Loukotová Lenka , Dodda Jagan M. , Bělský Petr , Kullová Lucie , Kadlec Jaroslav , Podivinská Martina , Vohlídal Jiří
Published: May 2017

New polyamic acids with ‐A‐B‐A‐C‐ type periodic sequence of monomeric units (A derived from a diamine, B from benzophenone‐3,3′,4,4′‐tetracarboxylic dianhydride, and C from benzene‐1,2,4,5‐tetracarboxylic dianhydride) are prepared and transformed into polyimide membranes that are examined by various methods in order to investigate the influence of diamine units (aliphatic, alicyclic, or aromatic) on the morphology, thermal stability, and mechanical properties of membranes. Small‐ and wide‐angle X‐ray scattering and Atomic force microscopy show amorphous character of all membranes except for those containing hexane‐1,6‐diamine units. Thermogravimetric analysis reveals a decrease in the initial decomposition temperature from 551/501 °C to 437/395 °C (for N2/O2 atmosphere) when going from membranes with aromatic to those with aliphatic diamine units. Dynamic mechanical analysis shows quite high initial storage modulus (2100–3300 MPa) for all membranes at frequencies of 1, 10, and 20 Hz. The properties of prepared copolymeric polyimide are promising for a wide range of their potential technological applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45227.
Cas6 processes tight and relaxed repeat RNA via multiple mechanisms: A hypothesis
Authors: Sefcikova Jana , Roth Mitchell , Yu Ge , Li Hong
Published: May 2017

RNA molecules are flexible yet foldable. Proteins must cope with this structural duality when forming biologically active complexes with RNA. Recent studies of the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs)‐mediated RNA immunity illustrate some remarkable mechanisms with which proteins interact with RNA. Currently known structures of CRISPR‐Cas6 endoribonucleases bound with RNA suggest a conserved protein recognition mechanism mediated by RNA stem‐loops. However, a survey of CRISPR RNA reveals that many repeats either lack a productive stem‐loop (Relaxed) or possess stable but inhibitory structures (Tight), which raises the question of how the enzyme processes structurally diverse RNA. In reviewing recent literature, we propose a bivalent trapping and an unwinding mechanism for CRISPR‐Cas6 to interact with the Relaxed and the Tight repeat RNA, respectively. Both mechanisms aim to create an identical RNA conformation at the cleavage site for accurate processing.
Development and validation of HPLC‐MS/MS method for the determination of lixivaptan in mouse plasma and its application in a pharmacokinetic study
Authors: Kadi Adnan A. , Alrabiah Haitham , Attwa Mohamed W. , Attia Sabry , Mostafa Gamal A. E.
Published: May 2017

The aim of the present study was to develop a simple, sensitive and accurate liquid chromatography–electrospray ionization tandem mass spectrometry (ESI‐MS/MS) method for the determination of lixivaptan (LIX) in mouse plasma using vildagliptin as the internal standard (IS). A precipitation procedure was used for the extraction of LIX and vildagliptin from mouse plasma. Chromatographic separation of LIX was achieved using a C18 analytical column (50 × 2.1 mm, 1.8 μm) at 25°C. The mobile phase comprised acetonitrile and ammonium formate (10 mm, pH 3.1; 40:60, v/v) pumped at a flow rate of 0.3 mL min−1. A tandem mass spectrometer with an electrospray ionization source was used to perform the assay. Quantification of LIX at m/z 290 → 137 and IS at 154 → 97 was attained through multiple reaction monitoring. The investigated method was authenticated following the bio‐analytical method of validation guidelines of the US Food and Drug Administration. The developed method showed a good linearity over the concentration range from 5 to 500 ng mL−1, and the calibration curve was linear (r = 0.9998). The mean recovery of LIX from mouse plasma was 99.2 ± 0.68%. All validation parameters for LIX were within the levels required for acceptance. The proposed method was effectively used for a pharmacokinetic study of LIX in mouse plasma.
Conformational Analysis of the Mannosidase Inhibitor Kifunensine: A Quantum Mechanical and Structural Approach
Authors: Males Alexandra , Raich Lluís , Williams Spencer J. , Rovira Carme , Davies Gideon J.
Published: May 2017

The varied yet family‐specific conformational pathways used by individual glycoside hydrolases (GHs) offer a tantalising prospect for the design of tightly binding and specific enzyme inhibitors. A cardinal example of a GH‐family‐specific inhibitor, and one that finds widespread practical use, is the natural product kifunensine, which is a low‐nanomolar inhibitor that is selective for GH family 47 inverting α‐mannosidases. Here we show, through quantum‐mechanical approaches, that kifunensine is restrained to a “ring‐flipped” 1C4 conformation with another accessible, but higher‐energy, region around the 1,4B conformation. The conformations of kifunensine in complex with a range of GH47 enzymes—including an atomic‐level resolution (1 Å) structure of kifunensine with Caulobacter sp. CkGH47 reported herein and with GH family 38 and 92 α‐mannosidases—were mapped onto the kifunensine free‐energy landscape. These studies revealed that kifunensine has the ability to mimic the product state of GH47 enzymes but cannot mimic any conformational states relevant to the reaction coordinate of mannosidases from other families.
Impact of pre‐existing or new‐onset atrial fibrillation on 30‐day clinical outcomes following transcatheter aortic valve replacement: Results from the BRAVO 3 randomized trial
Authors: Hengstenberg Christian , Chandrasekhar Jaya , Sartori Samantha , Lefevre Thierry , Mikhail Ghada , Meneveau Nicolas , Tron Christophe , Jeger Raban , Kupatt Christian , Vogel Birgit , Farhan Serdar , Sorrentino Sabato , Sharma Madhav , Snyder Clayton , Husser Oliver , Boekstegers Peter , Hambrecht Rainer , Widder Julian , Hildick‐Smith David , De Carlo Marco , Wijngaard Peter , Deliargyris Efthymios , Bernstein Debra , Baber Usman , Mehran Roxana , Anthopoulos Prodromos , Dangas George ,   for the BRAVO‐3 Investigators
Published: May 2017

Background

Prior studies have suggested that patients with atrial fibrillation (AF) undergoing transcatheter aortic valve replacement (TAVR) are at higher risk for adverse cardiovascular events. Whether procedural bivalirudin compared with unfractionated heparin (UFH) has a beneficial effect on early outcomes in these patients is unknown. We examined for the effect of baseline or new‐onset AF within 30 days of TAVR and explored for the effect of bivalirudin versus UFH by AF status, on 30‐day outcomes from the BRAVO 3 trial.

Methods

The BRAVO‐3 trial multicenter randomized trial included 802 patients undergoing transfemoral TAVR randomized to bivalirudin or UFH. We compared AF and no‐AF groups and examined for 30‐day Bleeding Academic Research Consortium type ≥3b bleeding, major vascular complications and all ischemic endpoints. Adjusted outcomes were analyzed using logistic regression methods.

Results

Of the study population, 41.4% (n = 332) patients had baseline or new‐onset AF within 30 days of TAVR, whereas 58.6% (n = 470) had no AF. Patients with AF had greater prevalence of renal dysfunction, lower left ventricular ejection fraction, and higher euroSCORE I compared with their counterparts without AF. Among AF and no‐AF patients, there were no significant baseline differences between bivalirudin and UFH groups. At 30 days the incidence of death (6.0 vs. 4.5%, P = 0.324) and stroke (3.9 vs. 2.6%, P = 0.274) was similar in AF vs. no‐AF patients. However, new‐onset AF (n = 38) was associated with significantly greater crude risk of 30‐day stroke compared with no AF (HR 4.49, 95% CI 1.37–14.67). Regardless of AF status, there were no differences in 30‐day death (P‐int = 0.652) or stroke (P‐int = 0.066) by anticoagulation type.

Conclusions

Prior or new‐onset AF is noted in more than one‐third of patients undergoing transfemoral TAVR. Despite greater baseline comorbidities than non‐AF patients, AF was not associated with significantly higher risk of adjusted 30‐day outcomes. In the BRAVO 3 trial, early outcomes were similar regardless of anticoagulant strategy in each group.
Oxidative C−C Cleavage of Ketols over Vanadium–Carbon Catalysts
Authors: Nakagawa Yoshinao , Sekine Dai , Obara Naoyuki , Tamura Masazumi , Tomishige Keiichi
Published: May 2017

The oxidation of 2‐hydroxycyclohexanone and carbohydrates to adipic acid and formic acid, respectively, was performed with a combination of a vanadium catalyst, carbon as the cocatalyst, and O2 in water under mild conditions (353 K, 0.1–0.3 MPa). The catalytic activity of aqueous V2O5 was increased significantly by the addition of activated carbon (C), whereas the addition of carbon black, graphene oxide, and carbon nanotubes has a much smaller effect. UV/Vis and inductively coupled plasma optical emission spectroscopy were used to show that most VV species are adsorbed on C at least in a short reaction time. The VIV species (VO2+) was not adsorbed on C. The order of activity of vanadium species was VV on C>dissolved free VV≫dissolved free VIV. To help the oxidation of VIV, the further addition of phosphomolybdate (PMo12O403−; PMo) was also tested, and the activity was improved. The selectivity and yield of adipic acid from 2‐hydroxycyclohexanone was also improved slightly by the addition of PMo. However, in the oxidation of glucose, the addition of PMo did not improve the final formic acid yield. The oxidation of glucose with the V+C system gave a 42 % yield of formic acid, which was comparable to the values reported with a more expensive PVMo polyoxometalate catalyst. A reaction mechanism is proposed in which the reversibly formed “biradical” state of the vanadium ketol complex reacts with O2 and accompanying rearrangement dissociates the C−C bond.
Inline Determination of Aqueous Diglycolamines CO2 Loading in Dependence of the Viscosity and Temperature
Authors: Köhler Martin , Schwarze Louisa , Ohle Andrea , Mollekopf Norbert
Published: May 2017

Die CO2‐Beladung eines Waschmittels (WM) ist bei der Beurteilung der Effizienz eines Absorptions‐/Desorptionsprozesses von entscheidender Bedeutung. Die Bestimmung über Inline‐Messverfahren ist jedoch kaum möglich. Eine Korrelation zur Bestimmung der CO2‐Beladung in Abhängigkeit von der WM‐Viskosität und ‐Temperatur wurde experimentell ermittelt. Die Korrelation konnte durch Kontrollmessungen und den Vergleich mit Literaturwerten verifiziert werden. Es ergab sich eine relative Abweichung von unter 10 %. Gleichzeitig wurde untersucht, ob der pH‐Wert und die elektrische Leitfähigkeit des WM ebenfalls geeignete Größen für eine Korrelation sind.
Experimental Investigation of the Reaction Network of Ethene to Propene over Ni/AlMCM‐41 Catalysts
Authors: Perea Leo Alvarado , Felischak Matthias , Wolff Tanya , Hamel Christof , Seidel‐Morgenstern Andreas
Published: May 2017

The reaction network of the ethene‐to‐propene (ETP) reaction over Ni/AlMCM‐41 catalysts was studied. This reaction consists of the dimerization of ethene, the isomerization of 1‐butene, and the metathesis of ethene and 2‐butene to propene. This work focused on the latter. ETP experiments followed by in situ diffuse reflectance infrared Fourier transform spectroscopy were carried out. Metathesis activities were evaluated by the isomerization of butenes, the metathesis of ethene and 2‐butene, and the retro‐metathesis of propene. Metathesis activities of Ni/AlMCM‐41 catalysts were not observed. Thus, a conjunct polymerization of ethene to propene is proposed.
Bioscouring and bleaching of knitted cotton fabrics in one‐step process using enzymatically generated hydrogen peroxide
Authors: Reis Crisleine Zottis , Fogolari Odinei , Oliveira Débora , de Arruda Guelli Ulson de Souza Selene Maria , de Souza Antônio Augusto Ulson
Published: May 2017

This research involves the study of knitted cotton fabric bleaching using hydrogen peroxide generated enzymatically. Initially the bioscouring was performed using the enzymes cellulose (EC. 3.2.1.4), pectinase (EC. 4.2.2.2), and lipase (EC. 3.1.1.3) to remove impurities. Then bleaching was performed using hydrogen peroxide, which was enzymatically produced by glucose oxidase (EC. 1.1.3.4) during oxidation of glucose. The generation of hydrogen peroxide and bleaching were assessed using experimental designs, where it was observed that the most significant effect to generate peroxide was time and for bleaching was the concentration of hydrogen peroxide. The whiteness and hydrophilicity of the treated knitted fabric were evaluated. The whiteness index of the enzymatically bleached fabric was 52 ± 1 °Berger with good hydrophilicity, by capillarity method 5.2 cm in 10 min. The results from this work demonstrate that this process can be an alternative for the textile preparation industry. There is a large reduction in water consumption compared to the conventional process. The water consumption is four times lower than the water consumption of the conventional process.
Conjugate Hydrocyanation of Chalcone Derivatives Using Ethyl Cyanoacetate as an Organic Cyanide Source
Authors: Li Zheng , Yin Junjun
Published: May 2017

The conjugate hydrocyanation of chalcone derivatives using ethyl cyanoacetate as an organic cyanide source at room temperature under open air and transition metal‐free conditions was described. The protocol has advantages of using relatively cheap, less toxic, stable and easy‐to‐handle cyanating reagent, high yield, and mild reaction condition.
KI Catalyzed Nitrogenation of Aldehydes and Alcohols: Direct Synthesis of Carbamoyl Azides and Ureas
Authors: Song Song , Feng Peng , Zou Miancheng , Jiao Ning
Published: May 2017

An efficient KI catalyzed nitrogenation of aldehydes and alcohols for the direct synthesis of carbamoyl azides and ureas via a radical process has been developed. The simple operating procedures, the readily available starting materials including aldehydes, alcohols and amines, as well as the utility of the products all make this strategy very attractive.
Rational Design and Synthesis of 1‐(Arylideneamino)‐4‐aryl‐1H‐imidazole‐2‐amine Derivatives as Antiplatelet Agents
Authors: Amidi Salimeh , Esfahanizadeh Marjan , Tabib Kimia , Soleimani Zohreh , Kobarfard Farzad
Published: May 2017

Based on previous studies indicating the pharmacophoric role of a hydrazone group and azole rings for antiplatelet aggregation activity, a few series of compounds with both hydrazone and an azole (imidazole) ring in their structures were synthesized, and their platelet aggregation inhibitory effects were evaluated. Two of these 1‐(arylideneamino)‐4‐aryl‐1H‐imidazole‐2‐amine derivatives, compounds 4 a [(E)‐1‐(benzylideneamino)‐4‐phenyl‐1H‐imidazol‐2‐amine] and 4 p [(E)‐4‐phenyl‐1‐((thiophen‐2‐ylmethylene)amino)‐1H‐imidazol‐2‐amine], exhibited IC50 values similar to that of acetylsalicylic acid against collagen as a platelet aggregation inducer. Structural comparison of the synthesized compounds revealed that those with a para‐substituted phenyl ring on the imidazole were among the most active compounds against platelet aggregation induced by arachidonic acid (AA), and the presence of a thiophene ring in these compounds maximized their antiplatelet activity.
Contribution of patient, physician, and environmental factors to demographic and health variation in colonoscopy follow‐up for abnormal colorectal cancer screening test results
Authors: Partin Melissa R. , Gravely Amy A. , Burgess James F. , Haggstrom David A. , Lillie Sarah E. , Nelson David B. , Nugent Sean M. , Shaukat Aasma , Sultan Shahnaz , Walter Louise C. , Burgess Diana J.
Published: May 2017

BACKGROUND

Patient, physician, and environmental factors were identified, and the authors examined the contribution of these factors to demographic and health variation in colonoscopy follow‐up after a positive fecal occult blood test/fecal immunochemical test (FOBT/FIT) screening.

METHODS

In total, 76,243 FOBT/FIT‐positive patients were identified from 120 Veterans Health Administration (VHA) facilities between August 16, 2009 and March 20, 2011 and were followed for 6 months. Patient demographic (race/ethnicity, sex, age, marital status) and health characteristics (comorbidities), physician characteristics (training level, whether primary care provider) and behaviors (inappropriate FOBT/FIT screening), and environmental factors (geographic access, facility type) were identified from VHA administrative records. Patient behaviors (refusal, private sector colonoscopy use) were estimated with statistical text mining conducted on clinic notes, and follow‐up predictors and adjusted rates were estimated using hierarchical logistic regression.

RESULTS

Roughly 50% of individuals completed a colonoscopy at a VHA facility within 6 months. Age and comorbidity score were negatively associated with follow‐up. Blacks were more likely to receive follow‐up than whites. Environmental factors attenuated but did not fully account for these differences. Patient behaviors (refusal, private sector colonoscopy use) and physician behaviors (inappropriate screening) fully accounted for the small reverse race disparity and attenuated variation by age and comorbidity score. Patient behaviors (refusal and private sector colonoscopy use) contributed more to variation in follow‐up rates than physician behaviors (inappropriate screening).

CONCLUSIONS

In the VHA, blacks are more likely to receive colonoscopy follow‐up for positive FOBT/FIT results than whites, and follow‐up rates markedly decline with advancing age and comorbidity burden. Patient and physician behaviors explain race variation in follow‐up rates and contribute to variation by age and comorbidity burden. Cancer 2017;123:3502‐12. Published 2017. This article is a US Government work and is in the public domain in the USA.
Noncovalent Interactions between Dopamine and Regular and Defective Graphene
Authors: Fernández Ana C. Rossi , Castellani Norberto J.
Published: May 2017

The role of noncovalent interactions in the adsorption of biological molecules on graphene is a subject of fundamental interest regarding the use of graphene as a material for sensing and drug delivery. The adsorption of dopamine on regular graphene and graphene with monovacancies (GV) is theoretically studied within the framework of density functional theory. Several adsorption modes are considered, and notably those in which the dopamine molecule is oriented parallel or quasi‐parallel to the surface are the more stable. The adsorption of dopamine on graphene implies an attractive interaction of a dispersive nature that competes with Pauli repulsion between the occupied π orbitals of the dopamine ring and the π orbitals of graphene. If dopamine adsorbs at the monovacancy in the A–B stacking mode, a hydrogen bond is produced between one of the dopamine hydroxy groups and one carbon atom around the vacancy. The electronic charge redistribution due to adsorption is consistent with an electronic drift from the graphene or GV surface to the dopamine molecule.