bluuebunny/crossref_metadata_2025_split huggingface dataset:
Soil Organic Carbon Sequestration in Jatropha curcas Systems in Burkina Faso
Authors: Baumert Sophia , Khamzina Asia , Vlek Paul L. G. 
Published: July 2014

AbstractThe cultivation of the biofuel crop Jatropha curcas L. in Burkina Faso may contribute to ameliorating the soil fertility of severely declining cropland through increased organic matter input and erosion control. This study addresses the potential for the soil organic carbon (SOC) sequestration in traditional and newly introduced J. curcas production systems. Five prevailing systems included interplanting with annual crops, intensely managed monoculture plantations, afforestation of abandoned cropland, plantings along contour stone walls, and traditional living fences.The SOC was analyzed in 20 paired sites of 1‐ to 4‐year‐old J. curcas plantings and adjacent cropland. Paired sites with living fences involved a longer chronosequence with 15‐ and 20‐year‐old plantings. Additionally, the contribution of J. curcas to SOC sequestration was investigated by comparing the 13C signature of the C inputs in four J. curcas sites with that of sorghum cropping.Linear regression analysis did not reveal a clear trend of SOC dynamics over time for the short‐term chronosequences, nor could the isotopic tracer technique prove a contribution of 4‐year‐old J. curcas trees to the SOC stock. The 20‐year chronosequence of J. curcas living fences exhibited a significant SOC increase of 62 ± 23 g m−2 y−1. Considering soil coverage of 1,200 m2 ha−1 by living fences (400‐m hedge with a width of 3 m), 1.5 Mg SOC was sequestered. Also, changes in δ13C values indicated a contribution of C3‐derived C to the SOC stock. These findings on traditional J. curcas systems indicate the potential of this biofuel crop for improving cropland soil fertility in the long run. Copyright © 2014 John Wiley & Sons, Ltd.
The Warburg Effect Revisited—Lesson from the Sertoli Cell
Authors: Oliveira Pedro F. , Martins Ana D. , Moreira Ana C. , Cheng C. Yan , Alves Marco G. 
Published: July 2014

AbstractOtto Warburg observed that cancerous cells prefer fermentative instead of oxidative metabolism of glucose, although the former is in theory less efficient. Since Warburg's pioneering works, special attention has been given to this difference in cell metabolism. The Warburg effect has been implicated in cell transformation, immortalization, and proliferation during tumorigenesis. Cancer cells display enhanced glycolytic activity, which is correlated with high proliferation, and thus, glycolysis appears to be an excellent candidate to target cancer cells. Nevertheless, little attention has been given to noncancerous cells that exhibit a “Warburg‐like” metabolism with slight, but perhaps crucial, alterations that may provide new directions to develop new and effective anticancer therapies. Within the testis, the somatic Sertoli cell (SC) presents several common metabolic features analogous to cancer cells, and a clear “Warburg‐like” metabolism. Nevertheless, SCs actively proliferate only during a specific time period, ceasing to divide in most species after puberty, when they become terminally differentiated. The special metabolic features of SC, as well as progression from the immature but proliferative state, to the mature nonproliferative state, where a high glycolytic activity is maintained, make these cells unique and a good model to discuss new perspectives on the Warburg effect. Herein we provide new insight on how the somatic SC may be a source of new and exciting information concerning the Warburg effect and cell proliferation.
The Hypocretin/Orexin System: An Increasingly Important Role in Neuropsychiatry
Authors: Chen Quanhui , de Lecea Luis , Hu Zhian , Gao Dong 
Published: July 2014

AbstractHypocretins, also named as orexins, are excitatory neuropeptides secreted by neurons specifically located in lateral hypothalamus and perifornical areas. Orexinergic fibers are extensively distributed in various brain regions and involved in a number of physiological functions, such as arousal, cognition, stress, appetite, and metabolism. Arousal is the most important function of orexin system as dysfunction of orexin signaling leads to narcolepsy. In addition to narcolepsy, orexin dysfunction is associated with serious neural disorders, including addiction, depression, and anxiety. However, some results linking orexin with these disorders are still contradictory, which may result from differences of detection methods or the precision of tools used in measurements; strategies targeted to orexin system (e.g., antagonists to orexin receptors, gene delivery, and cell transplantation) are promising new tools for treatment of neuropsychiatric disorders, though studies are still in a stage of preclinical or clinical research.
Vitamin K catabolite inhibition of ovariectomy‐induced bone loss: Structure–activity relationship considerations
Authors: Soper Robin J. , Oguz Cenk , Emery Roger , Pitsillides Andrew A. , Hodges Stephen J. 
Published: July 2014

ScopeThe potential benefit of vitamin K as a therapeutic in osteoporosis is controversial and the vitamin K regimen being used clinically (45 mg/day) employs doses that are many times higher than required to ensure maximal gamma‐carboxylation of the vitamin K‐dependent bone proteins. We therefore tested the hypothesis that vitamin K catabolites, 5‐carbon (CAN5C) and 7‐carbon carboxylic acid (CAN7C) aliphatic side‐chain derivatives of the naphthoquinone moiety exert an osteotrophic role consistent with the treatment of osteoporosis.Methods and resultsOsteoblast‐like MG63 cell cultures were challenged with lipopolysaccharide and the levels of interleukin‐6, an osteoclastogenic cytokine, measured with and without catabolites; low concentrations of CAN7C significantly inhibited interleukin‐6 release, but CAN5C did not. In models of bone loss induced by ovariectomy or sciatic neurectomy in C57BL/6 mice, we found that the rarer CAN7C catabolite markedly restricted ovariectomy‐induced bone loss and possibly limited sciatic neurectomy‐induced bone loss. CAN7C activity depends on a free carboxylic acid and its particular side‐chain structure.ConclusionThese in vivo data indicate for the first time that the clinical utility of vitamin K for osteoporosis may reside in an unusual catabolite.
Quantified pH imaging with hyperpolarized 13C‐bicarbonate
Authors: Scholz David Johannes , Janich Martin A. , Köllisch Ulrich , Schulte Rolf F. , Ardenkjaer‐Larsen Jan H. , Frank Annette , Haase Axel , Schwaiger Markus , Menzel Marion I. 
Published: July 2014

PurposeBecause pH plays a crucial role in several diseases, it is desirable to measure pH in vivo noninvasively and in a spatially localized manner. Spatial maps of pH were quantified in vitro, with a focus on method‐based errors, and applied in vivo.MethodsIn vitro and in vivo 13C mapping were performed for various flip angles for bicarbonate (BiC) and CO2 with spectral‐spatial excitation and spiral readout in healthy Lewis rats in five slices. Acute subcutaneous sterile inflammation was induced with Concanavalin A in the right leg of Buffalo rats. pH and proton images were measured 2 h after induction.ResultsAfter optimizing the signal to noise ratio of the hyperpolarized 13C‐bicarbonate, error estimation of the spectral‐spatial excited spectrum reveals that the method covers the biologically relevant pH range of 6 to 8 with low pH error (< 0.2). Quantification of pH maps shows negligible impact of the residual bicarbonate signal. pH maps reflect the induction of acute metabolic alkalosis. Inflamed, infected regions exhibit lower pH.ConclusionHyperpolarized 13C‐bicarbonate pH mapping was shown to be sensitive in the biologically relevant pH range. The mapping of pH was applied to healthy in vivo organs and interpreted within inflammation and acute metabolic alkalosis models. Magn Reson Med 73:2274–2282, 2015. © 2014 Wiley Periodicals, Inc.
On the calculation of cumulative strain around full‐flow penetrometers in steady‐state conditions
Authors: Osman Ashraf S. , Randolph Mark F. 
Published: July 2014

SummaryAn approximate solution for the effects of high strain rates, and gradual strength degradation, on the penetration resistance of penetrometers can be obtained by combining the strain‐path method with the classical upper bound theorem. The stream path calculations require the integration of the material constitutive equation along the streamlines. Unless the geometry is simple so that the integration can be evaluated analytically, numerical procedures are required to backtrack streamlines. The strain at any location is calculated by finding the streamline that passes through the given point and integrating the strain rate along that streamline from its inlet boundary. Thus, the calculations can be complicated, and errors can be accumulated during the calculation procedure.This paper presents an efficient approach for evaluating cumulative strains around penetrometers without the need to backtrack individual streamlines. In this approach, the strain components are treated as field variables. The global solution is obtained using the streamline upwind Petrov–Galerkin method. The new method together with an Eulerian‐based finite element formulation was used to study the cone penetration test and evaluate the effect of strain softening on the cone resistance. Copyright © 2014 John Wiley & Sons, Ltd.
A semi‐local spectral/hp element solver for linear elasticity problems
Authors: Yu Yue , Bittencourt Marco L. , Karniadakis George Em 
Published: July 2014

SUMMARYWe develop an efficient semi‐local method for speeding up the solution of linear systems arising in spectral/hp element discretization of the linear elasticity equations. The main idea is to approximate the element‐wise residual distribution with a localization operator we introduce in this paper, and subsequently solve the local linear system. Additionally, we decouple the three directions of displacement in the localization operator, hence enabling the use of an efficient low energy preconditioner for the conjugate gradient solver. This approach is effective for both nodal and modal bases in the spectral/hp element method, but here, we focus on the modal hierarchical basis. In numerical tests, we verify that there is no loss of accuracy in the semi‐local method, and we obtain good parallel scalability and substantial speed‐up compared to the original formulation. In particular, our tests include both structure‐only and fluid‐structure interaction problems, with the latter modeling a 3D patient‐specific brain aneurysm. Copyright © 2014 John Wiley & Sons, Ltd.
An efficient time‐domain perfectly matched layers formulation for elastodynamics on spherical domains
Authors: Sagiyama K. , Govindjee S. , Persson P.‐O. 
Published: July 2014

SUMMARYMany practical applications require the analysis of elastic wave propagation in a homogeneous isotropic media in an unbounded domain. One widely used approach for truncating the infinite domain is the so‐called method of perfectly matched layers (PMLs). Most existing PML formulations are developed for finite difference methods based on the first‐order velocity‐stress form of the elasticity equations, and they are not straight‐forward to implement using standard finite element methods (FEMs) on unstructured meshes. Some of the problems with these formulations include the application of boundary conditions in half‐space problems and in the treatment of edges and/or corners for time‐domain problems. Several PML formulations, which do work with FEMs have been proposed, although most of them still have some of these problems and/or they require a large number of auxiliary nodal history/memory variables. In this work, we develop a new PML formulation for time‐domain elastodynamics on a spherical domain, which reduces to a two‐dimensional formulation under the assumption of axisymmetry. Our formulation is well‐suited for implementation using FEMs, where it requires lower memory than existing formulations, and it allows for natural application of boundary conditions. We solve example problems on two‐dimensional and three‐dimensional domains using a high‐order discontinuous Galerkin (DG) discretization on unstructured meshes and explicit time‐stepping. We also study an approach for stabilization of the discrete equations, and we show several practical applications for quality factor predictions of micromechanical resonators along with verifying the accuracy and versatility of our formulation. Copyright © 2014 John Wiley & Sons, Ltd.
Synthesis of clickable hydrogels and linear polymers by type II photoinitiation
Authors: Murtezi Eljesa , Ciftci Mustafa , Yagci Yusuf 
Published: July 2014

AbstractA facile synthesis method for the preparation of clickable hydrogels and linear polymers is described. The strategy pertains to the photochemical generation of initiating radicals by hydrogen abstraction of excited camphorquinone from acetylenic alcohol followed by free radical polymerization. For hydrogels, poly(ethylene glycol) methyl ether methacrylate and poly(ethylene glycol) diacrylate were used in the system as monomer and crosslinker, respectively. Fluorescent pyrene groups were anchored onto the hydrogels through copper‐catalyzed Huisgen 1,3‐dipolar azide/alkyne click reaction by using 2‐azidomethyl pyrene as evidenced by Fourier transform infrared and fluorescence spectroscopy. The applicability of the method for macromolecular synthesis is also demonstrated. For this purpose, poly(methyl methacrylate) with alkyne terminal groups was prepared by photoinitiated free radical polymerization of methyl methacrylate using camphorquinone and 3‐(trimethylsilyl)propargyl alcohol as sensitizer and hydrogen donor, respectively. After deprotection, the click reaction with azido polystyrene obtained by atom transfer radical polymerization followed by azidation resulted in the formation of polystyrene‐b‐poly(methyl methacrylate). The intermediates at various stages and the final block copolymer were characterized by spectral analysis and gel permeation chromatography. © 2014 Society of Chemical Industry
Synthesis and Characterization of a Thermally and Hydrolytically Stable Energetic Material based on N‐Nitrourea
Authors: Cui Kejian , Xu Guangrui , Xu Zhibin , Wang Peng , Xue Min , Meng Zihui , Li Jiarong , Wang Bozhou , Ge Zhongxue , Qin Guangmin 
Published: July 2014

AbstractThe novel primary explosive tetranitrodiglycoluril (TNDGU) was synthesized from glycoluril dimer. It was fully characterized by using NMR (1H, 13C), IR spectroscopy, and elemental analysis. X‐ray diffraction revealed that the crystals of TNDGU belong to triclinic system with space group P$\bar 1$. The thermal behavior of TNDGU was studied using DSC methods. TNDGU exhibited good thermal stability with a decomposition temperature of 284.8 °C. TNDGU was also more resistant to hydrolysis compared to other nitrourea analogues. Additionally, density, enthalpy of formation, detonation velocity (VOD), and detonation pressure of TNDGU were predicted and it was found that TNDGU is a potential powerful explosive with a calculated density of 1.93 g cm−3, a detonation velocity of 8305 m s−1 and low sensitivity to electric discharge.
Nano Cyclotetramethylene Tetranitramine Particles Prepared by a Green Recrystallization Process
Authors: An Chongwei , Li Hequn , Guo Wenjian , Geng Xiaoheng , Wang Jingyu 
Published: July 2014

AbstractThe solubility of cyclotetramethylene tetranitramine (HMX) in four ionic liquids (ILs): 1,3‐dimethylimidazolium dimethylphosphate ([Memim]DMP), 1‐butyl‐3‐methylimidazolium chloride ([Bmim]Cl), 1‐hexyl‐3‐methylimidazolium bromide ([Hmim]Br), and 1‐ethyl‐3‐methylimidazolium tetrafluoroborate ([Emim]BF4) was investigated. Nano‐HMX were produced particles by spraying [Hmim]Br solution into purified ice water. Finally, the particle size, morphology, crystal phase, impact sensitivity, and thermal decomposition properties of nano‐HMX particles were tested and analyzed. All four ILs could dissolve HMX to a greater or lesser extent in the temperature range from 20 °C to 80 °C. The solubility of HMX in [Hmim]Br at 80 °C is up to 0.7 g mL−1. Recrystallized HMX particles are of polyhedral or spherical shape and 40 to 130 nm in size. X‐ray diffraction indicated that nano‐HMX has a similar crystal structure as raw HMX (β‐form). Compared with raw HMX, the nano‐HMX particles have much lower impact sensitivity. However, they are easier to explode than raw HMX under thermal stimulus due to the lower peak temperature and activation energy.
Thermal Decomposition, Kinetics and Compatibility Studies of Poly(3‐difluoroaminomethyl‐3‐methyloxetane) (PDFAMO)
Authors: Li Huan , Pan Renming , Wang Wanjun , Zhang Luyao 
Published: July 2014

AbstractThe thermal decomposition of poly(3‐difluoroaminomethyl‐3‐methyloxetane) (PDFAMO) with an average molecular weight of about 6000 was investigated using thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). The kinetics of thermolysis were studied by a model‐free method. The thermal decomposition of PDFAMO occurred in a two‐stage process. The first stage was mainly due to elimination of HF and had an activation energy of 110–120 kJ mol−1. The second stage was due to degradation of the polymer chain. The Fourier transform infrared (FTIR) spectra of the degradation residues showed that the difluoroamino groups decomposed in a two‐step HF loss at different temperatures. The remaining monofluoroimino groups produced by the incomplete elimination of HF were responsible for the two‐stage thermolysis process. The compatibility of PDFAMO with some energetic components and inert materials used in polymer‐bonded explosives (PBXs) and solid propellants was studied by DSC. It was concluded that the binary systems of PDFAMO with cyclotrimethylenetrinitramine (RDX), 2,4,6‐trinitrotoluene (TNT), 2,4‐dinitroanisole (DNAN), pentaerythritol tetranitrate (PETN), ammonium perchlorate (AP), aluminum powder (Al), aluminum oxide (Al2O3) and 1,3‐diethyl‐1,3‐diphenyl urea (C1) were compatible, whereas the systems of PDFAMO with lead carbonate (PbCO3) and 2‐nitrodiphenylamine (NDPA) were slightly sensitized. The systems with cyclotetramethylenetetranitroamine (HMX), hexanitrohexaazaisowurtzitane (CL‐20), 3‐nitro‐1,2,4‐triazol‐5‐one (NTO), ammonium nitrate (AN), magnesium powder (Mg), boron powder (B), carbon black (C. B.), diphenylamine (DPA), and p‐nitro‐N‐methylamine (PNMA) were incompatible. The results of compatibility studies fully supported the suggested thermal decomposition mechanism of PDFAMO.
Prospects for the control of apple leaf midge Dasineura mali (Diptera: Cecidomyiidae) by mass trapping with pheromone lures
Authors: Lo Peter L , Walker James TS , Suckling D Max 
Published: July 2014

AbstractBACKGROUNDApple leaf midge, Dasineura mali (Kieffer), poses quarantine issues for some apple export markets because larvae occasionally pupate in the stem end and calyx of fruit. Pheromone‐baited oil‐filled containers were used in 1 ha orchard plots to trap adult male D. mali in order to test the potential for mass trapping to reduce populations.RESULTSMass‐trapped plots had 97% fewer adult males in pheromone traps and 48% fewer larvae per shoot in the second D. mali generation compared with untreated areas. Oil traps caught on average 900 000 D. mali per plot over 11 weeks during the second and third generations. Catches averaged 9200 per trap at plot corners. By comparison, catches were 51% lower 10–25 m away along borders, 80% lower at the midpoint of borders and 95% lower >7 m from plot edges. Fruit infestation was low (four out of 8000 apples).CONCLUSIONThe attractiveness of the pheromone, monophagous habit and low mobility of D. mali enhance the prospects for successful mass trapping. Countering this are high populations, multivoltinism and aspects of mating behaviour. Mass trapping would probably have been more effective had it been in place season long and conducted over successive years. It needs refinements and more study before becoming a feasible control option for D. mali. © 2014 Society of Chemical Industry
Replicating Peer‐Led Team Learning in cyberspace: Research, opportunities, and challenges
Authors: Smith Joshua , Wilson Sarah Beth , Banks Julianna , Zhu Lin , Varma‐Nelson Pratibha 
Published: July 2014

AbstractThis quasi‐experimental, mixed methods study examined the transfer of a well‐established pedagogical strategy, Peer‐Led Team Learning (PLTL), to an online workshop environment (cPLTL) in a general chemistry course at a research university in the Midwest. The null hypothesis guiding the study was that no substantive differences would emerge between the two workshop settings. Students in the PLTL (n = 220) condition were more satisfied with their workshop and earned statistically significantly higher course grades, yet earned comparable standardized final exam scores. They also had lower incidence of students’ earning D or F course grades or withdrawing from the course (DFW rates) than students in the cPLTL setting (n = 175). Interviews with 10 peer leaders and 2 faculty members, as well as discourse analysis of workshop sessions, revealed more similarities than differences in the two conditions. The final exam scores and discourse analysis support the null hypothesis and use of both face‐to‐face and synchronous online peer‐led workshops in early science courses. © 2014 Wiley Periodicals, Inc. J Res Sci Teach 51: 714–740, 2014
Nanoparticle approaches against bacterial infections
Authors: Gao Weiwei , Thamphiwatana Soracha , Angsantikul Pavimol , Zhang Liangfang 
Published: July 2014

Despite the wide success of antibiotics, the treatment of bacterial infections still faces significant challenges, particularly the emergence of antibiotic resistance. As a result, nanoparticle drug delivery platforms including liposomes, polymeric nanoparticles, dendrimers, and various inorganic nanoparticles have been increasingly exploited to enhance the therapeutic effectiveness of existing antibiotics. This review focuses on areas where nanoparticle approaches hold significant potential to advance the treatment of bacterial infections. These areas include targeted antibiotic delivery, environmentally responsive antibiotic delivery, combinatorial antibiotic delivery, nanoparticle‐enabled antibacterial vaccination, and nanoparticle‐based bacterial detection. In each area we highlight the innovative antimicrobial nanoparticle platforms and review their progress made against bacterial infections. WIREs Nanomed Nanobiotechnol 2014, 6:532–547. doi: 10.1002/wnan.1282This article is categorized under:

Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease
Late Pleistocene sedimentary history of multiple glacially dammed lake episodes along the Yarlung-Tsangpo river, southeast Tibet
Authors: Huang Shao-Yi , Chen Yue-Gau , Burr George S. , Jaiswal Manoj K. , Lin Yunung Nina , Yin Gongming , Liu Jingwei , Zhao Shujun , Cao Zhongquan 
Published: July 2014

AbstractWe present a reconstructed lithologic column compiled from a series of lacustrine outcrops along a tributary of the Nyang River, a major tributary of the Yarlung-Tsangpo in southeast Tibet. The deposits were preserved between terraces at altitudes of 2950–3100 m asl. The stratigraphic record features at least two sets of coarsening-upward sequences depicting episodic aggradation and progradation of a glacially dammed lake related delta. Recognized facies changes illustrate the evolution cycles of depositional environments from pro-delta, delta front, to delta plain. Radiocarbon and optically stimulated luminescence dates reveal an aging-downward trend in stratigraphic order and provide an approximate timeline for the formation of glacially dammed lakes in late Pleistocene. This result reflects that the Zelunglung Glacier had progressively advanced to block the Yarlung-Tsangpo river and the dam materials had stepwise stacked up to an altitude of 3095 m asl during Marine Oxygen Isotope Stages 4 to 2.