bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elastic constants of lamellar and interlamellar regions in α and mesomorphic isotactic polypropylene by AFM indentation
Authors: Picu R. C. , Osta A. R. 
Published: April 2016

ABSTRACTA study of the nanoscale mechanical properties of isotactic mesomorphic and semi‐crystalline polypropylene (iPP) is presented. Two iPPs produced with metallocene and Ziegler‐Natta catalyst polymerization are used. The resulting fibers are characterized by wide angle X‐ray scattering, small‐angle X‐ray scattering (SAXS), and Raman spectroscopy. The spatial variability of the percentage crystallinity is evaluated based on the SAXS data. AFM indentation is performed to measure the elastic modulus of the fibers in the direction perpendicular and parallel to the fiber axis. Since the AFM probing is performed on a scale larger than the lamellar thickness, a statistical analysis of the AFM and SAXS data is necessary to infer the elastic moduli of the α crystals and of the inter‐lamellar regions. The elastic modulus of the crystalline lamellae in the direction perpendicular to the c‐axis of the α crystal probed in compression is estimated at approximately 3.3 GPa, while the effective modulus of the interlamellar regions ranges from 1.5 to 2.2 GPa. The method proposed can be applied to other material systems with similar layered structure to measure elastic moduli or hardness on length scales smaller than the resolution of the indentation test. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43649.
Unsicherheiten bei der Quantifizierung von Hochwasser‐Schadenspotenzialen
Authors: Schwarz Jochen , Maiwald Holger , Kaufmann Christian 
Published: April 2016

AbstractDie Ermittlung von Hochwasser‐Schadenspotenzialen bei Nutzen‐Kosten‐Analysen erfolgt in den einzelnen Bundesländern meist mit herkömmlichen nutzungsorientierten Schadensmodellen. Dabei geben Schadensfunktionen einen Erwartungswert (Mittelwert) für den zu erwartenden Schaden in Abhängigkeit von der Nutzung und den hochwasserspezifischen Einwirkungsparametern an. Die große Streubreite der real auftretenden Schäden wird dabei vernachlässigt.Im Beitrag werden die Auswirkungen der in diesen Modellen nicht berücksichtigten verletzbarkeitsbestimmenden Bauwerksparameter und verschiedener möglicher (flächennutzungskonformer) Bauwerksbestände durch Monte‐Carlo‐Simulationen untersucht.Für diese Simulationen werden mit dem verletzbarkeitsorientierten, mikroskaligen EDAC‐Hochwasserschadensmodell für reale Überflutungsszenarien die Streubreiten der potenziellen Verluste ermittelt.Die Ergebnisse veranschaulichen, dass diese Streubreiten in den Verlusten im Rahmen von Nutzen‐Kosten‐Analysen mit berücksichtigt werden sollten.Uncertainties in the quantification of flood damage potentialThe determination of flood damage potential in cost‐benefit analyses is carried out in the individual federal states mostly with conventional use‐oriented damage models. This type of damage functions provides expected values (average values) for the losses depending on the use and flood‐specific impact parameters. The large scatter of reported losses is neglected.The paper considers the impact of vulnerability determining building parameter and different possible (use compliant) building stocks on these models.On the basis of Monte Carlo simulations, the scatter of the potential losses is calculated applying the vulnerability based, microscale EDAC‐flood damage model for real flooding scenarios.The results illustrate that these uncertainties of the prognosis should be considered in the loss assessment and in particular for the scope of cost‐benefit decisions.
Die Tücken der Selbstheilung bei Weißen Wannen
Authors: Bastert Heinrich 
Published: April 2016

AbstractPlanung und Ausführung wasserundurchlässiger Betonkonstruktionen (WU‐Konstruktionen) sind in Deutschland seit 2003 in der WU‐Richtlinie des Deutschen Ausschusses für Stahlbeton e. V. (DAfStb) geregelt. Zu den Grundlagen der Bemessung von WU‐Konstruktionen nach WU‐Richtlinie gehört die Wahl eines Entwurfsgrundsatzes. Aus wirtschaftlichen Gründen wird oft der Entwurfsgrundsatz der Selbstheilung von Rissen bevorzugt. In diesem Beitrag werden Grundlagen des Selbstheilungsprozesses genannt und ihre Auswirkungen auf die Gebrauchstauglichkeit der WU‐Konstruktion aufgezeigt.Design of watertight concrete structures using autogenous healing of cracksThe design and execution of watertight concrete structures in Germany is regulated by the DAfStb guideline on watertight concrete structures from 2003 (WU‐Richtlinie). Fundamentals of the design of watertight concrete structures according to the WU‐Richtlinie refer to several options to solve the problem of possible cracks in concrete. Most practitioners prefer autogenous healing of cracks because it is an efficient and economical way to solve these problems. This paper provides some basic information on the autogenous healing process and the effects on the usability of watertight structures.
Zur Ermüdung von Beton und Stahlfaserbeton
Authors: Heek Peter , Mark Peter 
Published: April 2016

AbstractZur Beurteilung des Ermüdungsverhaltens von Werkstoffen wie Beton und Stahlfaserbeton unter zyklischer Beanspruchung konstanter Amplitude haben sich WÖHLERlinien etabliert. Im Einstufen‐Schwingversuch wird dabei eine Materialprobe einer zyklischen Beanspruchung bis zum Bruch ausgesetzt und die Anzahl aufnehmbarer Lastspiele logarithmiert als Funktion der Ermüdungslast aufgetragen. In der Literatur existiert eine Vielzahl empirischer WÖHLERlinien für z. B. normal‐ und hochfeste Betone ohne und mit Faserzusatz unter Schwell‐ oder Wechselbeanspruchung. Ein universell gültiger Ansatz fehlt hingegen bisher. Im Beitrag wird das Ermüdungsverhalten von Beton und Stahlfaserbeton verglichen und ein energetisches Duktilitätsmaß vorgestellt, das zur Klassifizierung der Betone geeignet ist und eine einheitliche Beschreibung des funktionalen Zusammenhanges von Bruchlastspielzahl und Ermüdungslast ermöglicht. Die mechanische Basis des Duktilitätsmaßes erlaubt zudem insbesondere für zyklisch biegezugbeanspruchte Stahlfaserbetone die gezielte Optimierung ermüdungsrelevanter Parameter wie Fasertyp und ‐menge. Anhand von Versuchsergebnissen aus der Literatur werden Genauigkeit und Allgemeingültigkeit des neuen Ansatzes verifiziert und an Beispielen vorgestellt.Fatigue of plain and steel fibre reinforced concreteTo assess fatigue‐life of plain and steel fibre reinforced concrete Wöhler‐ or rather SN‐curves are well established. Those curves providing information about logarithmised numbers of cycles until failure as a function of constant amplitude loading can easily be derived via testing. In literature, a huge number of empirical SN approaches are available, valid either for normal or high‐performance concrete containing variable amounts of fibres for instance. However, a more general approach is still missing. Subsequently, fatigue life of plain and steel fibre reinforced concrete at constant amplitude loading is contrasted yielding to modified but universally valid SN‐curves containing a new toughness index. The mechanically based toughness index is suitable to distinguish between plain and fibre reinforced concrete and allows for the optimization of fibre characteristics like type and dosage to ensure maximum fatigue life. Finally, the presented SN approach is verified using test data from literature. The results are in good accordance on average.
Calorespirometric feeding control enhances bioproduction from toxic feedstocks—Demonstration for biopolymer production out of methanol
Authors: Rohde Maria‐Teresa , Paufler Sven , Harms Hauke , Maskow Thomas 
Published: April 2016

ABSTRACTThe sustainable production of fuels and industrial bulk chemicals by microorganisms in biotechnological processes is promising but still facing various challenges. In particular, toxic substrates require an efficient process control strategy. Methanol, as an example, has the potential to become a major future feedstock due to its availability from fossil and renewable resources. However, besides being toxic, methanol is highly volatile. To optimize its dosage during microbial cultivations, an innovative, predictive process control strategy based on calorespirometry, i.e., simultaneous measurements of heat and CO2 emission rates, was developed. This rarely used technique allows an online‐estimation of growth parameters such as the specific growth rate and substrate consumption rate as well as a detection of shifts in microbial metabolism thus enabling an adapted feeding for different phases of growth. The calorespirometric control strategy is demonstrated exemplarily for growth of the methylotrophic bacterium Methylobacterium extorquens on methanol and compared to alternative control strategies. Applying the new approach, the methanol concentration could be maintained far below a critical limit, while increased growth rates of M. extorquens and higher final contents of the biopolymer polyhydroxybutyrate were obtained. Biotechnol. Bioeng. 2016;113: 2113–2121. © 2016 Wiley Periodicals, Inc.
Randomized multicentre trial comparing external and internal pancreatic stenting during pancreaticoduodenectomy
Authors: Jang J-Y , Chang Y R , Kim S-W , Choi S H , Park S J , Lee S E , Lim C-S , Kang M J , Lee H , Heo J S 
Published: April 2016

AbstractBackgroundThere is no consensus on the best method of preventing postoperative pancreatic fistula (POPF) after pancreaticoduodenectomy (PD). This multicentre, parallel group, randomized equivalence trial investigated the effect of two ways of pancreatic stenting after PD on the rate of POPF.MethodsPatients undergoing elective PD or pylorus-preserving PD with duct-to-mucosa pancreaticojejunostomy were enrolled from four tertiary referral hospitals. Randomization was stratified according to surgeon with a 1 : 1 allocation ratio to avoid any related technical factors. The primary endpoint was clinically relevant POPF rate. Secondary endpoints were nutritional index, remnant pancreatic volume, long-term complications and quality of life 2 years after PD.ResultsA total of 328 patients were randomized to the external (164 patients) or internal (164) stent group between August 2010 and January 2014. The rates of clinically relevant POPF were 24·4 per cent in the external and 18·9 per cent in the internal stent group (risk difference 5·5 per cent). As the 90 per cent confidence interval (−2·0 to 13·0 per cent) did not fall within the predefined equivalence limits (−10 to 10 per cent), the clinically relevant POPF rates in the two groups were not equivalent. Similar results were observed for patients with soft pancreatic texture and high fistula risk score. Other postoperative outcomes were comparable between the two groups. Five stent-related complications occurred in the external stent group. Multivariable analysis revealed that soft pancreatic texture, non-pancreatic disease and high body mass index (23·3 kg/m2 or above) predicted clinically relevant POPF.ConclusionExternal stenting after PD was associated with a higher rate of clinically relevant POPF than internal stenting. Registration number: NCT01023594 (https://www.clinicaltrials.gov).
Biophysikalische Chemie – vom Einzelmolekül zum Verständnis komplexer biologischer Maschinen
Authors: Winter Roland 
Published: April 2016

AbstractWährend Chemie, Biologie und Physik sich im letzten Jahrhundert weitgehend auseinandergelebt haben, ist in diesen Jahren die Tendenz zu sehen, dass sie wieder aufeinander zugehen und einander befruchten. Dies ist umso wichtiger, als es in der nun eingetretenen Postgenom‐Ära darum geht, die Regulation der Genaktivität und die Funktion und Interaktion der Proteine und anderer Biomoleküle in der Zelle zu verstehen, wodurch das molekulare Verständnis der Lebensvorgänge immer mehr in den Vordergrund naturwissenschaftlicher Forschungsarbeiten rückt.
Investigations and Experiments of Variances Filtering Technology in the Ensemble Data Assimilation
Authors: Bai‐Nian LIU , Wei‐Min ZHANG , Xiao‐Qun CAO , Yan‐Lai ZHAO , Qun‐Bo HUANG , Yu LUO 
Published: April 2016

AbstractAn experimental Ensemble Data Assimilation (YH‐EDA) system has been built with 10 ensemble members based on the operational YH4DVAR system. The system can provide flow‐dependent background‐error variances, which are superior to the operational ones both in structure and magnitude. However, the finite ensemble size implies a detrimental sampling noise for the variances estimation. To solve this problem, a spectral filtering technique is implemented to formulate a low‐passing filter. Taking into account the typical horizontal length scales of noise and signal, the filter can eliminate the sampling noise while extracting the signal of interest. In the ensemble variance filtering experimentations of the 9th typhoon “Jebi” in 2013, our results show that the 10‐members' filtered variances exhibit better performance than 30‐members's estimation. The successful implementation of the spectral filtering reduces the requirement of large ensemble size of Ensemble Data Assimilation system, which indicates that spectral filtering has become an important and necessary technology in EDA operational implementation.
Evaluating p97 Inhibitor Analogues for Potency against p97–p37 and p97–Npl4–Ufd1 Complexes
Authors: Gui Lin , Zhang Xiaoyi , Li Kelin , Frankowski Kevin J. , Li Shan , Wong Daniel E. , Moen Derek R. , Porubsky Patrick R. , Lin Henry J. , Schoenen Frank J. , Chou Tsui‐Fen 
Published: April 2016

AbstractWe previously found that the p97 cofactor, p47, significantly decreased the potency of some ATP‐competitive p97 inhibitors such as ML240 [2‐(2‐amino‐1H‐benzo[d]imidazol‐1‐yl)‐N‐benzyl‐8‐methoxyquinazolin‐4‐amine] and ML241 [2‐(2H‐benzo[b][1,4]oxazin‐4(3H)‐yl)‐N‐benzyl‐5,6,7,8 tetrahydroquinazolin‐4‐amine]. In this study, we aimed to evaluate inhibitor potencies against two additional p97 cofactor complexes, p97–p37 and p97–Npl4–Ufd1. We focused on these two cofactor complexes, because the protein sequence of p37 is 50 % identical to that of p47, and the Npl4–Ufd1 heterodimer (NU) is the most‐studied p97 cofactor complex. We screened 200 p97 inhibitor analogues for their ability to inhibit the ATPase activity of p97 alone and of p97–p37 and p97–NU complexes. In contrast to the effect of p47, p37 and NU did not significantly change the potencies of most of the compounds. These results highlight differences among p97 cofactors in influencing p97 conformation and effects of inhibitors on p97 complexes, as compared to p97 alone. Continued efforts are needed to advance the development of complex‐specific p97 inhibitors.
The role of infarct transmural extent in infarct extension: A computational study
Authors: Leong Chin‐Neng , Lim Einly , Andriyana Andri , Al Abed Amr , Lovell Nigel Hamilton , Hayward Christopher , Hamilton‐Craig Christian , Dokos Socrates 
Published: April 2016

SummaryInfarct extension, a process involving progressive extension of the infarct zone (IZ) into the normally perfused border zone (BZ), leads to continuous degradation of the myocardial function and adverse remodelling. Despite carrying a high risk of mortality, detailed understanding of the mechanisms leading to BZ hypoxia and infarct extension remains unexplored. In the present study, we developed a 3D truncated ellipsoidal left ventricular model incorporating realistic electromechanical properties and fibre orientation to examine the mechanical interaction among the remote, infarct and BZs in the presence of varying infarct transmural extent (TME). Localized highly abnormal systolic fibre stress was observed at the BZ, owing to the simultaneous presence of moderately increased stiffness and fibre strain at this region, caused by the mechanical tethering effect imposed by the overstretched IZ. Our simulations also demonstrated the greatest tethering effect and stress in BZ regions with fibre direction tangential to the BZ–remote zone boundary. This can be explained by the lower stiffness in the cross‐fibre direction, which gave rise to a greater stretching of the IZ in this direction. The average fibre strain of the IZ, as well as the maximum stress in the sub‐endocardial layer, increased steeply from 10% to 50% infarct TME, and slower thereafter. Based on our stress–strain loop analysis, we found impairment in the myocardial energy efficiency and elevated energy expenditure with increasing infarct TME, which we believe to place the BZ at further risk of hypoxia. Copyright © 2016 John Wiley & Sons, Ltd.
Graphene‐Wrapped Graphitic Carbon Hollow Spheres: Bioinspired Synthesis and Applications in Batteries and Supercapacitors
Authors: Song Lei , Xin Sen , Xu Da‐Wei , Li Hui‐Qin , Cong Huai‐Ping , Yu Shu‐Hong 
Published: April 2016

AbstractInspired by the egg‐like yolk–shell structure, a novel kind of graphene‐wrapped graphitic hollow carbon spheres (G‐graphitic HCS) was designed and fabricated by iron‐catalyzed carbonization of double‐coated polystyrene (PS) spheres. Herein, a thin carbon shell and hollow, hierarchically porous G‐graphitic HCS facilitate ionic transport, while also providing more active sites for the storage of ions. Both graphitic components result in a seamless and highly efficient transmission pathway for electrons. Thus, G‐graphitic HCS demonstrate admirable multifunctions in energy‐storage devices, including lithium batteries, sodium batteries, and supercapacitors. It delivers an unprecedentedly high initial discharge capacity of 2007 mA h g−1 at 0.1 A g−1, and preserves 92.4 % of the initial charge capacity after 100 cycles in a prototype lithium half‐cell. The present concept may shed light on designing the key materials for next‐generation energy‐storage devices.
Interpretation of Spectroscopic Markers of Hydrogen Bonds
Authors: Scheiner Steve 
Published: April 2016

AbstractQuantum calculations are used to examine whether an AH⋅⋅⋅D H‐bond is unambiguously verified by a downfield shift of the bridging proton's NMR signal or a red (or blue) shift of the AH stretching frequency in the IR spectrum. It is found that such IR band shifts will occur even if the two groups experience weak or no attractive force, or if they are drawn in so close together that their interaction is heavily repulsive. The mere presence of a proton‐acceptor molecule can affect the chemical shielding of a position occupied by a protondonor by virtue of its electron density, even if there is no H‐bond present. This density‐induced shielding is heavily dependent on position around the proton–acceptor atom, and varies from one group to another. Evidence of a hydrogen bond rests on the measurement of a proton deshielding in excess of what is caused purely by the presence of the proton acceptor species.
A lower bound on achievable rate of MRT precoding in multicell multiuser massive MIMO networks with Rician flat fading
Authors: Kazemi Mohammad , Aghaeinia Hassan 
Published: April 2016

SummaryA multicell multiuser massive multiple‐input‐multiple‐output (MIMO) network with Rician flat fading is considered. Given channel reciprocity, non‐orthogonal uplink channel training in conjunction with minimum mean square error channel estimation at the base stations are used to acquire channel state information. In the forward link, using maximal ratio transmission precoding, base stations send data to corresponding users. In this paper, first, a closed‐form expression for signal to interference and noise ratio and a lower bound on achievable rate are obtained for arbitrary number of base station antennas. Then, using random matrix theory, a simplified approximate expression for large number of base station antennas (i.e., massive MIMO scenario) are calculated. This simplified expression shows that in a multicell multiuser massive MIMO network with Rician flat fading, like Rayleigh fading, as the number of base station antennas goes to infinity, the effects of uncorrelated noise and intercell and intracell interferences tend to zero. The only factor limiting the performance of system is the correlated intercell interference, that is, pilot contamination, due to non‐orthogonality of channel training sequences in adjacent cells. Numerical results show that our obtained closed‐form expression is a good lower bound on sum‐rate for various system parameters. Copyright © 2016 John Wiley & Sons, Ltd.
Antinociceptive Interactions Between Meloxicam and Gabapentin in Neuropathic Pain Depend on the Ratio used in Combination in Rats
Authors: Espinosa‐Juárez Josué Vidal , Jaramillo‐Morales Osmar Antonio , Corona‐Ramos Janette Nallely , Medina‐López José Raúl , López‐Muñoz Francisco Javier 
Published: April 2016

Abstract

Preclinical Research

Neuropathic pain is particularly difficult to treat because of its diverse etiologies and underlying pathophysiological mechanisms. Drug combinations have been proposed to effectively treat some neuropathies. In the present study the interaction of five combinations of meloxicam and gabapentin, were studied to assess the possible synergistic antinociceptive response in neuropathic pain using the von Frey and acetone tests in rat models. Coadministration of meloxicam and gabapentin increased the antihyperalgesic or antiallodynic effects as compared with the compounds administered alone. The area under the curve (AUC) of the antihyperalgesic effects produced by the combination of the two drugs was generally similar to the theoretical sum of effects produced by each drug alone. However, the AUC of the antiallodynic effect produced by one combination (meloxicam 1.0 mg/kg + gabapentin 10 mg/kg) was greater than the theoretical sum of the effects produced by each drug alone. The type of final interaction on the drug combinations can be additive or cause potentiation of antinociceptive effects and depends on the proportion of each compound used in dosing. Drug Dev Res 77 : 134–142, 2016. © 2016 Wiley Periodicals, Inc.
Soil physical properties response to grassland conversion from cropland on the semi‐arid area
Authors: Wu Gao‐Lin , Liu Yu , Fang Nu‐Fang , Deng Lei , Shi Zhi‐Hua 
Published: April 2016

AbstractSoil physical properties crucially affect vegetation restoration on the semi‐arid Loess Plateau. Understanding how converting cropland into grassland affects soil physical properties is essential throughout a long‐term natural vegetation restoration chronosequence. The objectives of this study were to determine the effects of naturally restored grassland from cropland (wheat) on soil physical properties over time. Hence, we analysed the effects on various soil physical properties at different restoration ages (0, 5, 15 and 30 years). Our results revealed that soil physical properties changed dynamically in response to the land use change over time. Grassland restoration increases soil texture coarseness in the upper soil layer (0–5 cm). After a 15‐year restoration, soil hydraulic conductivity attained the maximum measured value, but in restoration age (to 30 years) did not further improve soil hydraulic conductivity. Restoration increased the field capacity and the soil water content under the restored grassland when compared with the cropland, but increases were not linearly related to the restoration age. Our study suggests that converting cropland into grassland improved the soil structure and soil–water conditions, and that the first 15 years of restoration was sufficient in order to achieve most of the improvements in soil physical properties. Our results will be helpful in providing soil hydraulic parameters to other researchers with the aim of improving the restored grassland to become more effective and sustainable on the semi‐arid area. Copyright © 2016 John Wiley & Sons, Ltd.