bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crystallization behavior of hyperbranched polyethylenes with different degree of branching
Authors: Luo Xiang , Huang Wei , Yan Deyue 
Published: July 2016

ABSTRACTHyperbranched polyethylenes (HBPEs) with different degree of branching (DB) and similar Mn are used to investigate the effect of branch structure on their crystallization behaviors. The crystal structure, isothermal, and non‐isothermal crystallization kinetics of HBPEs are studied by X‐ray diffraction and differential scanning calorimetry. The isothermal crystallization process is analyzed by the Avrami equation while the non‐isothermal crystallization process is analyzed through the Ozawa and Mo methods. The XRD results indicate that the crystallization ability of HBPEs is weakened with the introduction of branch structure, i.e., the crystallinity of HBPEs decreases with the increase of DB, and even tends to zero. The kinetics results of isothermal and non‐isothermal crystallization verify the peculiar effects of DB on the crystallization process of HBPEs. In detail, a little of branch structure can accelerate the crystallization process of HBPEs, however a large number of branch can inhibit it. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44127.
Light‐Induced Direct Arylation in the Solid Crystalline State as a Strategy Towards π‐Expanded Imidazoles
Authors: Skonieczny Kamil , Gryko Daniel T. 
Published: July 2016

Abstractπ‐Expanded imidazoles bearing the 2‐iodophenyl substituent at position 2 undergo direct photoinduced intramolecular arylation in the solid, crystalline state leading to large non‐planar heterocycles. An analogous reaction employing 2‐bromophenyl and 2‐chlorophenyl substituents is considerably slower. Such processes have never before been demonstrated to occur in crystals and have allowed the efficient synthesizes of structurally unique compounds containing either the phenanthro[9′,10′:4,5]imidazo[1,2‐f]phenanthridine moiety or structurally related skeletons. The reaction occurs in the thin crystalline layers irradiated with UV photons in an almost quantitative manner over 48–72 h. Several previously unknown architectures have been prepared using this methodology. Furthermore, the optical properties of these π‐expanded imidazoles can be altered with the addition of heteroatoms and/or electron‐donating groups.
Observer‐Based Adaptive L2 Disturbance Attenuation Control of Semi‐Active Suspension with MR Damper
Authors: Cheng Ming‐Xing , Jiao Xiao‐Hong 
Published: July 2016

AbstractA novel nonlinear observer‐based adaptive disturbance attenuation control strategy was proposed for a quarter semi‐active suspension system with a magneto‐rheological (MR) damper in light of the intrinsic nonlinearity, parameter uncertainty, state immeasurability and road randomness. Adaptive adjusting parameters were adopted to avoid the curve fitting and identification of the system parameters by a great deal of experimental data for shortening the development cycle of the control system. Based on the reduced‐order observer, the system states including the immeasurable virtual state of MR damper and inconveniently measured states of suspension system were estimated for the realistic frame of the proposed controller in practice. The dissipative system theory was utilized to reduce the influence of the road disturbance on the system control performance. Simulation results in the bump road and B‐class road indicate that, whether there are perturbations of the system parameters or not, the proposed control scheme always ensures a better performance on the suspension travel, ride comfort and handling stability in comparison with other existing methods.
A comparison of orbitally‐shaken and stirred‐tank bioreactors: pH modulation and bioreactor type affect CHO cell growth and protein glycosylation
Authors: Monteil Dominique T. , Juvet Valentin , Paz Jonathan , Moniatte Marc , Baldi Lucia , Hacker David L. , Wurm Florian M. 
Published: July 2016

Orbitally shaken bioreactors (OSRs) support the suspension cultivation of animal cells at volumetric scales up to 200 L and are a potential alternative to stirred‐tank bioreactors (STRs) due to their rapid and homogeneous mixing and high oxygen transfer rate. In this study, a Chinese hamster ovary cell line producing a recombinant antibody was cultivated in a 5 L OSR and a 3 L STR, both operated with or without pH control. Effects of bioreactor type and pH control on cell growth and metabolism and on recombinant protein production and glycosylation were determined. In pH‐controlled bioreactors, the glucose consumption and lactate production rates were higher relative to cultures grown in bioreactors without pH control. The cell density and viability were higher in the OSRs than in the STRs, either with or without pH control. Volumetric recombinant antibody yields were not affected by the process conditions, and a glycan analysis of the antibody by mass spectrometry did not reveal major process‐dependent differences in the galactosylation index. The results demonstrated that OSRs are suitable for recombinant protein production from suspension‐adapted animal cells. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1174–1180, 2016
Process performance and bacterial community dynamics of partial‐nitritation biofilters subjected to different concentrations of cysteine amino acid
Authors: Rodriguez‐Sanchez Alejandro , Munoz‐Palazon Barbara , Maza‐Marquez Paula , Gonzalez‐Lopez Jesus , Vahala Riku , Gonzalez‐Martinez Alejandro 
Published: July 2016

Partial‐nitritation processes are used for the biological treatment of high nitrogen‐low organic carbon effluents, such as anaerobic digestion reject water. The release of certain products generated during the anaerobic digestion process, such as amino acids, could potentially reduce the performance of these partial‐nitritation bioprocesses. To investigate this, four partial‐nitritation biofilters were subjected to continuous addition of 0, 150, 300, and 500 mg L−1 cysteine amino acid in their influents. The addition of the amino acid had an impact over the performance of the partial‐nitritation process and the bacterial community dynamics of the systems analyzed. Ammonium oxidation efficiency decreased with the addition of the amino acid, and a net nitrogen elimination occurred in presence of cysteine through the operation period. Bacterial community dynamics showed a decrease of Nitrosomonas species and a proliferation of putative heterotrophs with nitrification capacity, such as Pseudomonas, or denitrification capacity, such as Denitrobacter or Alicycliphilus. The addition of cysteine irreversible affected the bioreactors, which could not achieve the performance obtained before the addition of the amino acid. A mathematical predictive equation of the process performance depending on cysteine concentration added and operational time under such concentration was developed. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1254–1263, 2016
Effect of aeration and agitation on extractive fermentation of clavulanic acid by using aqueous two‐phase system
Authors: Viana Marques Daniela A. , Santos‐Ebinuma Valéria C. , Pessoa‐Júnior Adalberto , Porto Ana L. F. , Torres Beatriz Rivas , Converti Attilio 
Published: July 2016

In this work, the effects of agitation and aeration rates on aqueous two‐phase system (ATPS)‐based extractive fermentation of clavulanic acid (CA) by Streptomyces variabilis DAUFPE 3060 were investigated through a 22 full factorial design, where oxygen transfer rate (OTR) and oxygen uptake rate (OUR) were selected as the responses. Aeration rates significantly influenced cell growth, OUR, and CA yield, while OTR was practically the same in all the runs. Under the intermediate agitation (950 rpm) and aeration conditions (3.5 vvm) of the central point runs, it was achieved OTR of 1.617 ± 0.049 mmol L−1 h−1, OUR of 0.132 ± 0.030 mmol L−1 h−1, maximum CA production of 434 ± 4 mg L−1, oxygen mass transfer coefficient of 33.40 ± 2.01 s−1, partition coefficient of 66.5 ± 1.5, CA yield in the top and bottom phases of 75% ± 2% and 19% ± 1%, respectively, mass balance of 95% ± 4% and purification factor of 3.8 ± 0.1. These results not only confirmed the paramount role of O2 supply, broth composition and operational conditions in CA ATPS‐extractive fermentation, but also demonstrated the possibility of effectively using this technology as a cheap tool to simultaneously produce and recover CA. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1444–1452, 2016
Spatio‐Temporal Variation of Terpenoids in Wild Plants of Pentalinon andrieuxii
Authors: Hiebert‐Giesbrecht Mickel R. , Escalante‐Erosa Fabiola , García‐Sosa Karlina , Dzib Gabriel R. , Calvo‐Irabien Luz M. , Peña‐Rodríguez Luis M. 
Published: July 2016

Pentalinon andrieuxii (Müll.Arg.) B.F.Hansen & Wunderlin (Apocynaceae) is a vine native to the Yucatan peninsula, where it is widely used in Mayan traditional medicine to treat, among other ailments, the wounds caused by cutaneous leishmaniasis. Among the secondary metabolites isolated from P. andrieuxii are the triterpene betulinic acid and the chemically unusual tri‐norsesquiterpene urechitol A; however, to date, there is no existing knowledge about the accumulation dynamics of the ubiquitous betulinic acid or the novel urechitol A in the plant. In this article, we report on the accumulation of both secondary metabolites in wild individuals of P. andrieuxii; our results show that while the content of betulinic acid in plant leaves bears no apparent relation to plant ontogeny, the content of urechitol A in root tissue is clearly related to plant development.
Prebiotic‐Like Condensations of Cyanamide and Glyoxal: Revisiting Intractable Biotars
Authors: Lavado Nieves , Escamilla Juan Carlos , Ávalos Martín , Babiano Reyes , Cintas Pedro , Jiménez José Luis , Palacios Juan Carlos 
Published: July 2016

AbstractWe report a detailed investigation into the nature of products that are generated by the reactions of cyanamide and glyoxal, two small molecules of astrochemical and prebiotic significance, under different experimental conditions. The experimental data suggest that the formation of oligomeric structures is related in part to the formation of insoluble tholins in the presence of oxygen‐containing molecules. Although oligomerization proceeds well in water, product isolation turned out to be impractical. Instead, solid precipitates were obtained easily in acetone. Crude mixtures have been thoroughly scrutinized by spectroscopic methods, in particular NMR and mass spectroscopy (ESI mode), which are all consistent with the generation of a few functional groups that are embedded into regular chains of five‐ and six‐membered rings, thereby pointing to a supramolecular organization. Three different models of cross‐condensation and chain growth are suggested. These synthetic explorations provide further insights into the formation of complex organic matter in interstellar scenarios and extraterrestrial bodies that might have played a pivotal role in chemical evolution.
Modelling of binary fluidized bed reactors for the sorption‐enhanced steam methane reforming process
Authors: Chao Zhongxi , Zhang Yuanwei , Wang Yuefa , Jakobsen Jana P. , Jakobsen Hugo A. 
Published: July 2016

ABSTRACTA 1 m high laboratory‐scale and a 4 m high industrial‐scale sorption‐enhanced steam methane reforming (SE‐SMR) fluidized bed reactor were simulated using a three‐fluid model. The performance of the SE‐SMR process was compared with the steam methane reforming (SMR) process. The influences of the superficial gas velocities and the solid loading (packed bed heights) on the reactor performance (hydrogen purity) were studied. The simulation results show that a higher purity of the hydrogen product can be obtained in a SE‐SMR reactor. The superficial gas velocity is an important parameter. In the present study, it has been found that the binary sorbent‐catalyst particles are well mixed when the bed is operated at m/s. The sorbent can adsorb CO steadily, thus the dry mole fraction of the hydrogen product can get above 0.95 in the 1 m laboratory‐scale bed, and above 0.97 in the 4 m industrial‐scale bed. However, when the laboratory scale bed is operated at a lower superficial gas velocity of m/s, the binary sorbent‐catalyst particles are segregated. When the bed is operated at a higher superficial gas velocity of 0.3 m/s, the process work load is increased, and the gas residence time in the reactor is decreased. Therefore, the hydrogen product purity is further decreased. The simulation results also show that there is an optimal bed height limit for the 4 m industrial‐scale bed, at which further increase of the packed bed height cannot increase the hydrogen purity.
Decelerating and Trapping Large Polar Molecules
Authors: Patterson David 
Published: July 2016

AbstractManipulating the motion of large polyatomic molecules, such as benzonitrile (C6H5CN), presents significant difficulties compared to the manipulation of diatomic molecules. Although recent impressive results have demonstrated manipulation, trapping, and cooling of molecules as large as CH3F, no general technique for trapping such molecules has been demonstrated, and cold neutral molecules larger than 5 atoms have not been trapped (M. Zeppenfeld, B. G. U. Englert, R. Glöckner, A. Prehn, M. Mielenz, C. Sommer, L. D. van Buuren, M. Motsch, G. Rempe, Nature 2012, 491, 570–573). In particular, extending Stark deceleration and electrostatic trapping to such species remains challenging. Here, we propose to combine a novel “asymmetric doublet state” Stark decelerator with recently demonstrated slow, cold, buffer‐gas‐cooled beams of closed‐shell volatile molecules to realize a general system for decelerating and trapping samples of a broad range of volatile neutral polar prolate asymmetric top molecules. The technique is applicable to most stable volatile molecules in the 100–500 AMU range, and would be capable of producing trapped samples in a single rotational state and at a motional temperature of hundreds of mK. Such samples would immediately allow for spectroscopy of unprecedented resolution, and extensions would allow for further cooling and direct observation of slow intramolecular processes such as vibrational relaxation and Hertz‐level tunneling dynamics.
Formyl‐Modified Polyaniline for the Catalytic Dehydration of Fructose to 5‐Hydroxymethylfurfural
Authors: Zhu Liangfang , Dai Jinhang , Liu Mingyang , Tang Dianyong , Liu Shuqing , Hu Changwei 
Published: July 2016

AbstractWe report an unprecedented solid organic‐base catalyst, formyl‐modified polyaniline (FS‐PAN), for the dehydration of fructose to 5‐hydroxymethylfurfural (HMF) with a high yield of 90.4 mol %. We demonstrate that the nitrogen atoms incorporated between the phenyl rings in the backbone of the polyaniline chain contribute to the basicity of the catalyst. The grafting of electron‐withdrawing formyl groups to the imine nitrogen atoms leads to a significant increase of basicity of the polymer catalyst owing to the greater localization of electrons at the amide nitrogen atom formed. A linear dependence of the yield of HMF on the grafting level of formyl groups in FS‐PAN indicates that the amide acts as the active phase. A possible reaction mechanism for this organic‐base‐catalyzed dehydration reaction is proposed. The side‐reaction of HMF rehydration is inhibited thoroughly, and the condensation of any reaction intermediates to undesirable oligomers is restrained by this base catalyst. This organic‐base catalyst can be recycled completely without loss of activity. This research highlights the first application of a highly effective and stable solid base catalyst for the transformation of renewable carbohydrates into fine chemicals.
QoS‐Aware MAC protocols utilizing sectored antenna for wireless sensor networks‐based smart grid applications
Authors: Yigit Melike , Durmaz Incel Ozlem , Baktir Selcuk , Gungor V. Cagri 
Published: July 2016

SummaryWireless sensor networks (WSNs) are the most commonly deployed technology in smart grid environments owing to their advantages including low cost and successful adoption in various harsh smart grid environments. However, providing the quality of service (QoS) requirements of smart grid applications with WSNs is difficult because of the power constraints of sensor nodes and unreliable wireless links. In order to meet the QoS requirements of smart grid applications using WSNs, in this paper, we first propose a QoS‐aware omnidirectional antenna‐based medium access control (QODA‐MAC). Then, in order to investigate the impact of using sectored antennas on meeting QoS requirements, we also propose another QoS‐aware four‐sectored antenna‐based MAC protocol (QFSA‐MAC). The aim of the proposed approaches is to increase channel utilization with efficient service differentiation considering traffic flows with different requirements as well as providing reliable and fast delivery of data. We measure the performance of QODA‐MAC and QFSA‐MAC by making extensive simulations and compare them with each other. The results show that QFSA‐MAC outperforms the QODA‐MAC protocol and satisfies QoS requirements of smart grid applications by achieving significant improvement in terms of latency, energy consumption and data delivery. Copyright © 2016 John Wiley & Sons, Ltd.
Novel 5‐Hydroxy, 5‐Substituted Benzenesulfonamide Pyrimidine‐2,4,6‐Triones Attenuate Lipopolysaccharide‐Induced Acute Lung Injury via Inhibition of the Gelatinases, MMP‐2 and MMP‐9
Authors: He Wei , Jiang Jie , Yu Ze‐Qian , Zhou Jia‐Hua 
Published: July 2016

Abstract

Preclinical Research

A novel series of ten 5‐hydroxy, 5‐substituted benzene sulfonamide pyrimidine‐2,4,6‐triones were synthesized and their structures ascertained using 1H‐NMR, 13C‐NMR, mass and elemental analysis. These compounds were subsequently tested for inhibition of MMP‐2 and MMP‐9 where most exhibited activity with compound 5i being the most potent against MMP‐2 and MMP‐9 with IC50 values of 2.35 nM and 8.24 nM, respectively. Compound 5i was further analyzed in a mouse LPS‐induced acute lung injury model where it had protective activity. Histochemical studies indicated that 5i improved the vascular integrity of the lung. Drug Dev Res 77 : 251–257, 2016. © 2016 Wiley Periodicals, Inc.
Absence of net long‐term successional facilitation by alder in a boreal Alaska floodplain
Authors: Stuart Chapin F. , Conway Alexandra J. , Johnstone Jill F. , Hollingsworth Teresa N. , Hollingsworth Jamie 
Published: July 2016

AbstractLong‐term experiments provide a way to test presumed causes of successional or environmentally driven vegetation changes. Early‐successional nitrogen (N)‐fixing plants are widely thought to facilitate productivity and vegetation development on N‐poor sites, thus accounting for observed vegetation patterns later in succession. We tested this facilitative impact on vegetation development in a 23‐yr field experiment on an Interior Alaska (USA) floodplain. On three replicate early‐successional silt bars, we planted late‐successional white spruce (Picea glauca) seedlings in the presence and absence of planted seedlings of an early‐successional N‐fixing shrub, thinleaf alder (Alnus incana). Alder initially facilitated survivorship and growth of white spruce. Within six years, however, after canopy closure, alder negatively affected spruce survivorship and growth. Our three replicate sites followed different successional trajectories. One site was eliminated by erosion and supported no vegetation development during our study. The other two sites, which differed in site moisture, diverged in vegetation composition. Structural equation modeling (SEM) suggested that, in the drier of these two sites, alder inhibited spruce growth directly (presumably by competition) and indirectly through effects mediated by competition with other woody species. However, at the wetter site, alder had both positive and negative effects on spruce growth, with negative effects predominating. Snowshoe hares (Lepus americanus) in alder thickets further reduced height growth of spruce in the wetter site. We conclude that net effects of alder on white spruce, the late‐successional dominant, were primarily inhibitory and indirect, with the mechanisms depending on initial site moisture. Our results highlight the importance of long‐term research showing that small differences among initial replicate sites can cause divergence in successional trajectories, consistent with individualistic distributions of species and communities along environmental gradients. This divergence was detectable only decades later.
Garlic oil reduces ruminal fatty acid biohydrogenation in vitro
Authors: Doreau Michel , Arturo‐Schaan Marisela , Laverroux Sophie 
Published: July 2016

Nutritional policies recommend that animal products should be made to contain more polyunsaturated FA, especially n‐3 FA. This means finding ways to limit ruminal lipolysis and/or biohydrogenation. In pursuit of this goal, we performed an in vitro study to test the ability of four feed additives, typically used for other purposes, to reduce ruminal biohydrogenation of a linolenic acid‐rich substrate. The four additives tested were cinnamon essential oil, brown algae (Ascophyllum nodosum), synthetic vitamin E, and garlic essential oil. The first three additives had no effect on ruminal fermentation and biohydrogenation. Garlic essential oil led to a decrease in methane production (P < 0.001), an increase in propionate (P = 0.002) and butyrate (P < 0.001) production at the expense of acetate (P < 0.001), and a decrease in biohydrogenation evaluated by the disappearance of linolenic acid (P = 0.083) and linoleic acid (P = 0.008). Stearic acid proportion in FA decreased, while biohydrogenation intermediates such as C18:2t11c15 and vaccenic acid proportion increased (P < 0.001).Practical applications: Garlic essential oil emerges as a promising additive for decreasing biohydrogenation, but its efficiency needs to be confirmed in vivo in different dietary conditions, and possible side effects of the incorporation of garlic oil in diets will have to be evaluated.When garlic oil is added to a control substrate in an incubator containing rumen contents, biohydrogenation of linolenic acid (18:3c9c12c15) is reduced, and proportion of different unsaturated FA increases at the expense of stearic acid (18:0) which decreases from 71.8 to 62.2%. If this is confirmed in vivo, this may contribute to reduce saturated FA in milk and meat from ruminants.