bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biomechanical and finite element analyses of bone cement‐Injectable cannulated pedicle screw fixation in osteoporotic bone
Authors: Liu Yaoyao , Xu Jianzhong , Sun Dong , Luo Fei , Zhang Zehua , Dai Fei 
Published: May 2015

AbstractThe objectives of this study were to investigate the safety and biomechanical stability of a polymethylmethacrylate (PMMA)‐augmented bone cement‐injectable cannulated pedicle screw (CICPS) in cancellous bone model, and to analyze the stress distribution at the screw‐cement‐bone interface. The OMEGA cannulated pedicle screw (OPS) and conventional pedicle screw (CPS) were used as control groups. Safety of the CICPS was evaluated by the static bending and bending fatigue tests. Biomechanical stability was analyzed by the maximum axial pullout strength and maximum torque tests. Stress distribution at the screw–cement–bone interface was analyzed by the finite element (FE) method. The CICPS and CPS produced statistically similar values for bending stiffness, bending structural stiffness, and bending yield moment. The maximum pullout force was 53.47 ± 8.65 N in CPS group, compared to 130.82 ± 7.32 N and 175.45 ± 43.01 N in the PMMA‐augmented OPS and CICPS groups, respectively (p < 0.05). The CICPS had a significantly greater torque than the OPS and CPS. The FE model did not reveal excessive stress at the screw‐cement‐bone interface in the CICPS group. In conclusion, PMMA‐augmentation with CICPS may be a potentially useful method to increase the stability of pedicle screws in patients with osteoporosis. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 960–967, 2016.
Improved biomechanical and biological outcomes in the MRL/MpJ murine strain following a full‐length patellar tendon injury
Authors: Lalley Andrea L. , Dyment Nathaniel A. , Kazemi Namdar , Kenter Keith , Gooch Cynthia , Rowe David W. , Butler David L. , Shearn Jason T. 
Published: May 2015

ABSTRACTMusculoskeletal injuries greatly affect the U.S. population and current clinical approaches fail to restore long‐term native tissue structure and function. Tissue engineering is a strategy advocated to improve tendon healing; however, the field still needs to establish biological benchmarks for assessing the effectiveness of tissue‐engineered structures. Investigating superior healing models, such as the MRL/MpJ, offers the opportunity to first characterize successful healing and then apply experimental findings to tissue‐engineered therapies. This study seeks to evaluate the MRL/MpJ's healing response following a central patellar tendon injury compared to wildtype. Gene expression and histology were assessed at 3, 7, and 14 days following injury and mechanical properties were measured at 2, 5, and 8 weeks. Native patellar tendon biological and mechanical properties were not different between strains. Following injury, the MRL/MpJ displayed increased mechanical properties between 5 and 8 weeks; however, early tenogenic expression patterns were not different between the strains. Furthermore, expression of the cyclin‐dependent kinase inhibitor, p21, was not different between strains, suggesting an alternative mechanism may be driving the healing response. Future studies will investigate collagen structure and alignment of the repair tissue and characterize the complete healing transcriptome to identify mechanisms driving the MRL/MpJ response. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1693–1703, 2015.
Long‐term fertilization effects on soil organic carbon stocks in the irrigated desert soil of NW China
Authors: Chai Yanjun , Ma Shiming , Zeng Xibai , E Shengzhe , Che Zongxian , Li Lianfang , Duan Ran , Su Shiming 
Published: May 2015

AbstractSoil samples from the Hexi Corridor located at the arid regions of NW China were collected from a 23‐y‐old field experiment. Effects of fertilization on soil organic C (SOC) fractions and the distribution of added OC in the different SOC fractions were studied. The results showed that the long‐term applications of sole organic manures or in combination with inorganic N fertilizer significantly (P< 0.05) increased the OC stocks in the particulate organic matter (POM), light fraction organic matter (LFOM), and heavy fraction organic matter (HFOM) by 24.8–159.6%, 55.2–224.4%, and 6.2–57.8%, respectively, compared to the non‐fertilized treatment (CK). The average OC stock in the HFOM was higher than those of the POM and LFOM, and the conversion rate of the added OC to the OC stock of the HFOM was also higher than those of the POM and the LFOM, showing that SOC was mainly sequestrated in the HFOM. The increase of OC stock in the HFOM resulted in the increase of OC stocks in the loosely bound humus, stably bound humus, and tightly bound humus. The OC stocks in the loosely, stably, and tightly bound humus accounted averagely for 16, 19, and 65% of the OC stock in the HFOM. Furthermore, the conversion rates of the added OC to the OC stocks of loosely, stably and tightly bound humus were 2.3%, 1.5%, and 5.5%, respectively. Additionally, a significant (P< 0.01) positive linear correlation was found between the annually added OC amounts and the C sequestration rate. These results indicated that tightly bound humus was the most important component for OC sequestration in the irrigated desert soils of the Hexi Corridor and that SOC is not saturated in this region.
Soil N2O emissions following cover‐crop residues application under two soil moisture conditions
Authors: Pimentel Laisa Gouveia , Weiler Douglas Adams , Pedroso Gabriel Munhoz , Bayer Cimélio 
Published: May 2015

AbstractCover crops in rotation or intercropped with annual crops are important strategies to increase C and N input in agricultural soils. However, these practices may also enhance soil N2O emissions. The effect on N2O emissions may be dependent upon the biochemical composition of cover crop residues. A 47‐d incubation study was conducted to determine soil N2O emissions following the addition of residues from three summer legume species [pigeon pea (Cajanus cajan L. Millsp.), cowpea (Vigna unguiculata L. Walp.), lablab bean (Lablab purpureus)], one winter legume [vetch (Vicia sativa L.)], one winter monocotyledon [black oat (Avena strigosa Schreb.)], and maize (Zea mays L.) under two water‐filled pore space levels (40 and 70% WFPS). Short‐term peaks of N2O fluxes were observed after the addition of all crop residues, but were much greater under 70 than 40% WFPS (5.2 and 5133 µg N‐N2O kg−1 soil for 40 and 70% WFPS, respectively). Under both WFPS, significantly higher peaks were detected after the application of N‐rich legume residues (7.7 and 3,356 µg N‐N2O kg−1 soil under 40 and 70% WFPS, respectively) than after the application of grass residues (2.8 and 1,777 µg N‐N2O kg−1 soil under 40 and 70% WFPS, respectively). Cumulative soil N2O produced under 70% WFPS was approx. 110 times greater than under 40% WFPS. Soil N2O emissions increased linearly as residue N content increased. Soil N2O emissions also increased linearly as the content of the recalcitrant compounds lignin and polyphenols increased, because residues with high N content also had high lignin and polyphenols content. When the content of C and recalcitrant compounds were expressed on an N basis, soil N2O emission decreased linearly as residue C/N, lignin/N, polyphenol/N, and (lignin + polyphenols)/N ratios increased. Indices that include recalcitrant compounds on N basis may be useful for the selection of cover‐crop species with the least impact on soil N2O emissions. However, our results show that these ratio indices had similar correlation coefficients compared to C/N ratio, indicating that C/N ratio is an efficient index to predict soil N2O emission following cover crop application.
The nitrate transporter NRT1.1 is involved in iron deficiency responses in Arabidopsis
Authors: Liu Xunyan , Cui Haoqiang , Li Anna , Zhang Ming , Teng Yibo 
Published: May 2015

AbstractIron (Fe) deficiency strongly induces Fe‐acquisition gene expression. The nitrate transporter NRT1.1, which functions as a dual‐affinity nitrate transporter and nitrate signaling sensor, is involved in many nitrate‐dependent responses. However, the regulation of plant responses to Fe deficiency by NRT1.1 has not been described. In this study, it is shown that NRT1.1 is down‐regulated by Fe deficiency. The functional disruption of NRT1.1 enhanced resistance to Fe deficiency stress: after 10 d Fe starvation, the shoot chlorosis phenotype of the NRT1.1‐deficient mutant chl1‐5 was alleviated compared to the wild type (WT). Furthermore, the levels of IRT1, FRO2, and FIT transcripts were less induced in chl1‐5 plants under Fe‐deficient conditions. Less nitrate accumulated in chl1‐5 plants compared to WT and nitrate reductase (NR) activity was significantly decreased in WT plants after 10 d Fe deficiency treatment but not in the mutant. We propose that the functional disruption of NRT1.1 helps Arabidopsis plants to better adapt to Fe deficiency stress, which is most likely explained in terms of a physiological mechanism by which the reduced amount of accumulated internal nitrate could to impair an FIT‐dependent Fe deficiency signaling pathway via a feedback mechanism.
Observations of tidal and storm surge attenuation in a large tidal marsh
Authors: Stark J. , Van Oyen T. , Meire P. , Temmerman S. 
Published: May 2015

AbstractTidal wetlands are increasingly valued for their role in coastal defense. Nevertheless, in situ observations of storm surge attenuation within wetlands are still scarce. We present water level measurements along a 4 km intertidal channel and on the surrounding marsh platform for regular spring to neap tides and two major storm surge tides, showing the effects of flood wave height and marsh geomorphology on the amount of flood wave attenuation. Undermarsh tides with peak water levels below marsh platform elevation are mostly amplified (up to 4 cm/km) within the channels. Overmarsh tides with peak water levels above the marsh platform are generally attenuated along the channels, with maximum attenuation rates of 5 cm/km for tides that inundate the marsh platform by 0.5–1.0 m. For lower or higher flood waves, including storm surges, attenuation rates decrease. Furthermore, the observations show that the maximum attenuation occurs along narrow channel transects where the width of the platform is larger, whereas attenuation rates are lower along wider channels with smaller adjacent marsh platforms. These observations are confirmed by an analytical approximation of tidal wave propagation through convergent channels. The analytical model indicates that differences in attenuation rates are induced by variations in the cross‐channel averaged friction between channel sections and between tides with varying peak water levels. Finally, the highest attenuation rates of up to 70 cm/km are observed over short distances on the vegetated marsh platform. We conclude that this study provides an empirical basis for the wider implementation of nature‐based flood defense strategies.
Experimental O‐space turbo spin echo imaging
Authors: Wang Haifeng , Tam Leo , Kopanoglu Emre , Peters Dana C. , Constable R. Todd , Galiana Gigi 
Published: May 2015

PurposeTurbo spin echo (TSE) imaging reduces imaging time by acquiring multiple echoes per repetition (TR), requiring fewer TRs. O‐space can also require fewer TRs by using a combination of nonlinear magnetic gradient fields and surface coil arrays. Although to date, O‐space has only been demonstrated for gradient echo imaging, it is valuable to combine these two techniques. However, collecting multiple O‐space echoes per TR is difficult because of the different local k‐space trajectories and variable T2‐weighting.Theory and MethodsA practical scheme is demonstrated to combine the benefits of TSE and O‐space for highly accelerated T2‐weighted images. The scheme uses a modified acquisition order and filtered projection reconstruction to reduce artifacts caused by T2 decay, while retaining T2 contrast that corresponds to a specific echo time.ResultsThe experiments revealed that the proposed method can produce highly accelerated T2‐weighted images. Moreover, the method can generate multiple images with different T2 contrasts from a single dataset.ConclusionsThe proposed O‐space TSE imaging method requires fewer echoes than conventional TSE and fewer repetitions than conventional O‐space imaging. It retains resilience to undersampling, clearly outperforming Cartesian SENSE at high levels of undersampling, and can generate undistorted images with a range of T2 contrast from a single acquired dataset. Magn Reson Med 75:1654–1661, 2016. © 2015 Wiley Periodicals, Inc.
The dynamic and stochastic knapsack Problem with homogeneous‐sized items and postponement options
Authors: Feng Tianke , Hartman Joseph C. 
Published: May 2015

AbstractThis article generalizes the dynamic and stochastic knapsack problem by allowing the decision‐maker to postpone the accept/reject decision for an item and maintain a queue of waiting items to be considered later. Postponed decisions are penalized with delay costs, while idle capacity incurs a holding cost. This generalization addresses applications where requests of scarce resources can be delayed, for example, dispatching in logistics and allocation of funding to investments. We model the problem as a Markov decision process and analyze it through dynamic programming. We show that the optimal policy with homogeneous‐sized items possesses a bithreshold structure, despite the high dimensionality of the decision space. Finally, the value (or price) of postponement is illustrated through numerical examples. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 267–292, 2015
Changing the paradigm: Simulation, now a method of first resort
Authors: Lucas Thomas W. , Kelton W. David , Sánchez Paul J. , Sanchez Susan M. , Anderson Ben L. 
Published: May 2015

AbstractDecades ago, simulation was famously characterized as a “method of last resort,” to which analysts should turn only “when all else fails.” In those intervening decades, the technologies supporting simulation—computing hardware, simulation‐modeling paradigms, simulation software, design‐and‐analysis methods—have all advanced dramatically. We offer an updated view that simulation is now a very appealing option for modeling and analysis. When applied properly, simulation can provide fully as much insight, with as much precision as desired, as can exact analytical methods that are based on more restrictive assumptions. The fundamental advantage of simulation is that it can tolerate far less restrictive modeling assumptions, leading to an underlying model that is more reflective of reality and thus more valid, leading to better decisions. Published 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 293–303, 2015
User‐centric versus network‐centric load balancing: How to provide good QoE for gold users
Authors: Mämmelä Olli , Mannersalo Petteri 
Published: May 2015

SummaryThe predicted increase in mobile data traffic and in the number of mobile users poses challenges for network operators. Future mobile networks should support traffic volumes of several orders of magnitude larger than today. This may create situations in which the transmission capacity of the network is inadequate for the traffic demand. Intelligent and robust network management methods are thus needed to handle the upcoming changes. Because quite often the bottleneck lies in the wireless part of the network, it is essential to have methods in place to select appropriate wireless access points for the users or their applications. This can be performed either by a central entity or in a distributed manner in which the intelligence is placed in the user equipment or hybrid combinations of those. The selection criteria may vary from selfish optimization of a single user's quality of experience to global network load balancing and class‐wise prioritization. This work explores the wireless access selection scheme from a system perspective in scenarios where users of different subscription classes are using progressive video streaming. Evaluation is carried out between a Q‐learning based user‐centric algorithm, a user class aware network‐centric algorithm and a setting without handovers. Simulation results show that both user‐centric and network‐centric algorithms are able to improve the network performance and the quality of experience of the users. The gains of the network‐centric algorithm are more evident during high congestion. In a lightly congested network, the distributed selfish optimization is also qualitatively a good solution for gold users. Copyright © 2015 John Wiley & Sons, Ltd.
Computational homogenization of nonlinear elastic materials using neural networks
Authors: Le B. A. , Yvonnet J. , He Q.‐C. 
Published: May 2015

SummaryIn this work, a decoupled computational homogenization method for nonlinear elastic materials is proposed using neural networks. In this method, the effective potential is represented as a response surface parameterized by the macroscopic strains and some microstructural parameters. The discrete values of the effective potential are computed by finite element method through random sampling in the parameter space, and neural networks are used to approximate the surface response and to derive the macroscopic stress and tangent tensor components. We show through several numerical convergence analyses that smooth functions can be efficiently evaluated in parameter spaces with dimension up to 10, allowing to consider three‐dimensional representative volume elements and an explicit dependence of the effective behavior on microstructural parameters like volume fraction. We present several applications of this technique to the homogenization of nonlinear elastic composites, involving a two‐scale example of heterogeneous structure with graded nonlinear properties. Copyright © 2015 John Wiley & Sons, Ltd.
Fractional visco‐elastic Timoshenko beam deflection via single equation
Authors: Pirrotta Antonina , Cutrona Stefano , Lorenzo Salvatore Di , Matteo Alberto Di 
Published: May 2015

SummaryThis paper deals with the response determination of a visco‐elastic Timoshenko beam under static loading condition and taking into account fractional calculus. In particular, the fractional derivative terms arise from representing constitutive behavior of the visco‐elastic material. Further, taking advantages of the Mellin transform method recently developed for the solution of fractional differential equation, the problem of fractional Timoshenko beam model is assessed in time domain without invoking the Laplace‐transforms as usual. Further, solution provided by the Mellin transform procedure will be compared with classical Central Difference scheme one, based on the Grunwald–Letnikov approximation of the fractional derivative.Moreover, Timoshenko beam response is generally evaluated by solving a couple of differential equations. In this paper, expressing the equation of the elastic curve just through a single relation, a more general procedure, which allows the determination of the beam response for any load condition and type of constraints, is developed. Copyright © 2015 John Wiley & Sons, Ltd.
Arylnaphthalene and aryltetralin‐type lignans in hairy root cultures of Linum perenne, and the stereochemistry of 6‐methoxypodophyllotoxin and one diastereoisomer by HPLC‐MS and NMR spectroscopy
Authors: Jullian‐Pawlicki Nathalie , Lequart‐Pillon Michelle , Huynh‐Cong Luyen , Lesur David , Cailleu Dominique , Mesnard François , Laberche Jean Claude , Gontier Eric , Boitel‐Conti Michèle 
Published: May 2015

AbstractIntroductionHairy root cultures of Linum sp. are an alternative for the high production of lignans. Linum perenne is known to produce arylnaphthalene‐type lignans such as justicidin B, isojusticidin and diphyllin.ObjectiveTo elucidate the presence of aryltetralin‐type lignan diastereoisomers, besides the known arylnaphthalene‐type lignans, in hairy roots of Linum perenne, and to determine the configurations of one diastereoisomer of 6‐methoxypodophyllotoxin (6‐MPTOX).MethodsLignans from hairy root cultures of Linum perenne were extracted and separated by HPLC. Arylnaphthalene‐type lignans were identified by LC‐MS, according to the literature. Two diastereoisomers of aryltetralin‐type lignans were analysed by mass spectrometry and NMR spectroscopy.ResultsNumerous arylnaphthalene‐type lignans (diphyllin‐2‐hexose‐pentose, diphyllin‐3‐pentose and diphyllin‐hexose) were identified in hairy root cultures. Methoxypodophyllotoxin, an aryltetralin‐type lignan, was also identified, as well as one diastereoisomer. This aryltetralin‐type lignan could be derived via 7‐hydroxymatairesinol as a hypothetical biosynthetic pathway. The stereochemical configurations of aryltetralin isomers were determined.ConclusionArylnaphthalene and two diastereoisomers of aryltetralin‐type lignans are produced in Linum perenne hairy root cultures. Matairesinol, the precursor of justicidin B, also seems to be converted into 6‐MPTOX via 7‐hydroxymatairesinol. This is the first report of the stereochemical configurations of an aryltetralin‐type lignan other than podophyllotoxin (PTOX). Copyright © 2015 John Wiley & Sons, Ltd.
Prenatal diagnosis of Pierre Robin Sequence: accuracy and ability to predict phenotype and functional severity
Authors: Lind Katia , Aubry Marie‐Cécile , Belarbi Nadia , Chalouhi Christel , Couly Gérard , Benachi Alexandra , Lyonnet Stanislas , Abadie Véronique 
Published: May 2015

AbstractObjectiveTo assess the outcome of fetuses who had sonographic features suggestive of Pierre Robin Sequence (PRS).MethodAll prenatal ultrasounds that mentioned ‘posterior cleft palate’, or ‘micro or retrognathia’ or ‘PRS’ over 13 and 20 years, respectively, at two obstetrical centers were reviewed. Medical records for children with isolated PRS monitored over 20 years at a PRS referral center for prenatal anomalies and the severity of neonatal feeding and respiratory functional disorders were utilized for comparison.ResultsFrom a prenatal ultrasound database of 166 000 cases, 157 had one or more of the sonographic signs suggestive of PRS and had follow‐up available. Of them, 33 (21%) had confirmed PRS, 9 (6%) were normal and 115 (73%) had chromosomal aberrations, associated malformations or neurological anomalies. Visualization of a posterior cleft palate in addition to retro‐micrognathia had a positive predictive value of 100% for PRS. The distribution of functional severity grades was similar in cases suspected prenatally as in 238 cases of PRS followed in the referral center in Necker Hospital.ConclusionOnly a minority of cases of fetal retrognathia have complete PRS; the majority have other severe conditions. Prenatal prediction of functional severity of isolated PRS is not possible. © 2015 John Wiley & Sons, Ltd.