bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of osteopontin‐guided collagen intrafibrillar mineralization on pericyte differentiation and vascularization of engineered bone scaffolds
Authors: França Cristiane M. , Thrivikraman Greeshma , Athirasala Avathamsa , Tahayeri Anthony , Gower Laurie B. , Bertassoni Luiz E. 
Published: September 2018

AbstractBiomimetically mineralized collagen scaffolds are promising for bone regeneration, but vascularization of these materials remains to be addressed. Here, we engineered mineralized scaffolds using an osteopontin‐guided polymer‐induced liquid‐precursor mineralization method to recapitulate bone's mineralized nanostructure. SEM images of mineralized samples confirmed the presence of collagen with intrafibrillar mineral, also EDS spectra and FTIR showed high peaks of calcium and phosphate, with a similar mineral/matrix ratio to native bone. Mineralization increased collagen compressive modulus up to 15‐fold. To evaluate vasculature formation and pericyte‐like differentiation, HUVECs and hMSCs were seeded in a 4:1 ratio in the scaffolds for 7 days. Moreover, we used RT‐PCR to investigate the gene expression of pericyte markers ACTA2, desmin, CD13, NG2, and PDGFRβ. Confocal images showed that both nonmineralized and mineralized scaffolds enabled endothelial capillary network formation. However, vessels in the nonmineralized samples had longer vessel length, a larger number of junctions, and a higher presence of αSMA+ mural cells. RT‐PCR analysis confirmed the downregulation of pericytic markers in mineralized samples. In conclusion, although both scaffolds enabled endothelial capillary network formation, mineralized scaffolds presented less pericyte‐supported vessels. These observations suggest that specific scaffold characteristics may be required for efficient scaffold vascularization in future bone tissue engineering strategies. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1522–1532, 2019.
Phomopsis liquidambari colonization promotes continuous cropping peanut growth by improving the rhizosphere microenvironment, nutrient uptake and disease incidence
Authors: Xie Xing‐Guang , Zhang Feng‐Min , Wang Xing‐Xiang , Li Xiao‐Gang , Dai Chuan‐Chao 
Published: September 2018

AbstractBACKGROUNDThe continuous cropping of peanuts is a primary cause of yield and quality loss. Solutions to this problem should be therefore developed to ensure the sustainability of peanut production.RESULTSIn this study, colonization by the endophytic fungus Phomopsis liquidambari was detected, which led to significantly improved rhizosphere soil microenvironment, enhanced N, P and K assimilation and suppressed incidence of peanut disease. Statistical analysis demonstrated that the yield enhancement was significantly correlated with improvement of the rhizosphere soil microenvironment and the peanut's physiological status by P. liquidambari colonization. In addition, P. liquidambari colonization also significantly improved peanut quality.CONCLUSIONOur results indicate that the practical application of the endophytic fungus P. liquidambari has a strong potential to alleviate the obstacles associated with continuous peanut cropping under field conditions. © 2018 Society of Chemical Industry
iTRAQ proteomics reveals changes in the lettuce (Lactuca sativa L. Grand Rapid) proteome related to colour and senescence under modified atmosphere packaging
Authors: Chen Si , Chen Xiangning , Fan Junfeng , Liu Huijun , Zhou Jing , Chang Xiguang 
Published: September 2018

AbstractBACKGROUNDThis study used the isobaric tags for relative and absolute quantitation (iTRAQ) technique to determine the effects of active modified atmosphere packaging (MAP) on the modulation of lettuce (Lactuca sativa L. Grand Rapid) colour and senescence. Lettuces, treated or not treated (control) with MAP, were placed in a refrigerator (4 °C, 90–95% relative humidity) for analysis at 3‐day intervals until the ninth day.RESULTSMAP treatment could suppress weight loss, loss of green colour and brittleness, and browning of lettuce; at the same time, MAP preserved the green colour of lettuce by inhibiting chlorophyll degradation and chloroplast disruption, and delayed lettuce senescence by inhibiting malondialdehyde (MDA) generation and increasing antioxidant enzyme activity. In total, 285 differentially abundant proteins (144 upregulated proteins and 141 downregulated proteins) were identified in MAP‐treated and non‐treated lettuce. Further analysis revealed that MAP regulated the expression of proteins involved in photosynthesis (e.g. pheophorbide a oxygenase, PaO; porphobilinogen deaminase, PBGD), and thus preserved lettuce colour. The iTRAQ analysis also showed that MAP regulated the expression of antioxidant enzymes and reduced the accumulation of reactive oxygen species, and thus delayed lettuce senescence.CONCLUSIONMAP can maintain vegetable quality by inhibiting chlorophyll degradation, delaying vegetable senescence. © 2018 Society of Chemical Industry
Extraction and determination of tricyclic antidepressants in real samples using air‐dispersed liquid–liquid microextraction prior to gas chromatography and flame ionization detection
Authors: Mofazzeli Farideh , Asaadi Shirvan Homeira , Mohammadi Fatemeh 
Published: September 2018

AbstractIn the present research, a novel microextraction method was used based on dispersive liquid–liquid microextraction using low‐density solvent for the determination of trace amounts of amitriptyline and doxepin as model compounds in human plasma and spring water samples before gas chromatography and flame ionization detection. The parameters influencing the extraction efficiencies including type of the extracting solvent, volume of the aqueous sample solution (donor phase), volume of the extraction solvent (acceptor phase), the number of air‐injection, and the effects of pH and ionic strength were optimized. Under the optimized conditions, the obtained enrichment factors were >80. By plotting peak areas of the sample solutions versus various concentrations of the analytes, calibration curves were obtained which show the linear ranges of 10–3000 ng/mL with correlation coefficients of >0.996. The precision of the method was calculated <4.2 and the limit of detection was 1 ng/mL for two analytes. The proposed microextraction method was used for the extraction of the analytes in environmental water and plasma samples and the calculated relative recoveries were all >91%.
Selective magnetic nanographene oxide solid‐phase extraction with high‐performance liquid chromatography and fluorescence detection for the determination of zearalenone in corn samples
Authors: Thongprapai Pornpimol , Cheewasedtham Wilairat , Chong Kwok Feng , Rujiralai Thitima 
Published: September 2018

AbstractA magnetic nanographene oxide sorbent as a selective sorbent for the magnetic solid‐phase extraction combined with high‐performance liquid chromatography and fluorescence detection was developed and proved to be a robust method for zearalenone determination in corn samples. Optimum extraction of zearalenone (20 mg magnetic nanographene oxide sorbent, extraction for 15 min, desorption time of 15 min using 1 mL of 0.5% formic acid in methanol) resulted in low limits of detection (05 mg/L) and quantitation (0.13 mg/L) and good linearity range of 0.13–1.25 mg/L with the correlation coefficient of 0.9957. Acceptable recoveries (79.3–80.6%) with relative standard deviations below 4% and satisfactory intra‐ and interday precisions (2–7.4%) were achieved. Additionally, the proposed method has been proved to be good in several aspects: easily prepared sorbent with high affinity to zearalenone, convenient and fast procedure, and high extraction efficiency.
Weak‐harmonic regularization for quantitative susceptibility mapping
Authors: Milovic Carlos , Bilgic Berkin , Zhao Bo , Langkammer Christian , Tejos Cristian , Acosta‐Cabronero Julio 
Published: September 2018

PurposeBackground‐field removal is a crucial preprocessing step for quantitative susceptibility mapping (QSM). Remnants from this step often contaminate the estimated local field, which in turn leads to erroneous tissue‐susceptibility reconstructions. The present work aimed to mitigate this undesirable behavior with the development of a new approach that simultaneously decouples background contributions and local susceptibility sources on QSM inversion.MethodsInput phase data for QSM can be seen as a composite scalar field of local effects and residual background components. We developed a new weak‐harmonic regularizer to constrain the latter and to separate the 2 components. The resulting optimization problem was solved with the alternating directions of multipliers method framework to achieve fast convergence. In addition, for convenience, a new alternating directions of multipliers method–based preconditioned nonlinear projection onto dipole fields solver was developed to enable initializations with wrapped‐phase distributions. Weak‐harmonic QSM, with and without nonlinear projection onto dipole fields preconditioning, was compared with the original (alternating directions of multipliers method–based) total variation QSM algorithm in phantom and in vivo experiments.ResultsWeak‐harmonic QSM returned improved reconstructions regardless of the method used for background‐field removal, although the proposed nonlinear projection onto dipole fields method often obtained better results. Streaking and shadowing artifacts were substantially suppressed, and residual background components were effectively removed.ConclusionWeak‐harmonic QSM with field preconditioning is a robust dipole inversion technique and has the potential to be extended as a single‐step formulation for initialization with uncombined multi‐echo data.
A Comparison of Recall Error in Recreational Fisheries Surveys with One- and Two-Month Reference Periods
Authors: Andrews William R. , Papacostas Katherine J. , Foster John 
Published: September 2018

Abstract
Many fisheries monitoring programs use self-administered surveys to collect data, which are subject to recall error. Recall error occurs when respondents inaccurately remember past events due to telescoping (remembering events more recently or further back in time than they occurred) or omission error (forgetting events altogether). Previous research on the effects of variable reference periods in fisheries surveys has been inconclusive due to difficulty in disentangling method effects from recall error and in determining whether estimates from shorter recall periods are less biased or more subject to telescoping. The National Marine Fisheries Service has developed a new household mail survey, the Fishing Effort Survey (FES), in which anglers are asked to recall cumulative fishing effort over the past 2 months, from which estimates of saltwater fishing effort are produced. Here, we examined how the length of the reference period may affect the FES in four U.S. states by comparing effort estimates to two feasible alternatives: (1) a survey administered monthly with both a 1- and 2-month reference period (wherein respondents were asked to recall fishing effort for each of the past 2 months individually); and (2) a survey administered monthly with a 1-month reference period. To further explore bias in the designs, we compared total effort, fishing prevalence, and mean trips per household estimates derived from the two experimental surveys. We found no significant differences between the FES and experimental survey estimates. However, we found evidence that multiple reference periods in a single survey may reduce bias for 1-month estimates. Increased understanding of (1) techniques that can reduce recall bias and (2) the trade-offs of shorter or longer reference periods will ultimately help fisheries survey designers more accurately weigh bias against survey costs and improve the quality of data used to inform management decisions.
Synthesis and characterisation of fluorescent pyrene‐end‐capped polylactide fibres
Authors: Alwattar Aula , Haddad Athir , Zhou Quan , Nascimento Tatiana , Greenhalgh Ryan , Medeiros Eliton , Blaker Jonny , Parry Adam , Quayle Peter , Yeates Stephen 
Published: September 2018

AbstractFluorescent markers are critical for tracking the position and movement of molecules both in vivo and in vitro. Conventionally, synthetic dyes are non‐covalently added to polymers for fluorescent tracking, but often diffuse away. Here we demonstrate, for the first time, a facile method for the synthesis of fluorescent poly(lactic acid) nano‐/microfibres for biomedical applications using solution spin blowing. Pyrene‐end‐capped poly(l‐lactide) (PLLA) derivatives were synthesised using the ring‐opening polymerisation of l‐lactide and they were characterised using spectroscopic and thermal analyses. Submicrometre‐sized fluorescent fibres were produced from these PLLA derivatives using solution blow spinning techniques generating polymer blends and core–shell fibres. Such system could be further exploited to incorporate electrically conductive carbon allotropes via the pyrene aromaticity, producing fluorescent and electrically active fibres for in vitro monitoring and electrical stimulation. © 2018 Society of Chemical Industry
Laser welding of polymers using unsymmetrical squaraine dyes
Authors: Bak Helle Østergren , Nielsen Bjarne Enrico , Jeppesen Anne , Brock‐Nannestad Theis , Nielsen Christian Benedikt Orea , Pittelkow Michael 
Published: September 2018

ABSTRACTTransmission laser welding of plastic is typically achieved by incorporating a laser absorbing dye into one of the two pieces of plastic one wishes to weld together and mediating the welding process using a laser emitting light at a suitable wavelength. Desirable properties of laser absorbing dyes include: (1) the dye is colorless in the visible region but absorbs strongly in the region at the wavelength where the laser emits, (2) the dye has a good conversion of the energy from the laser to heat, (3) the dye is stable enough to be incorporated into the molten plastic, (4) the dye is soluble in the plastic of choice to give an even distribution in the plastic, and (5) the dye is nontoxic. Here, we explore an alternative approach to achieve laser welding of colorless plastics using a laser dye that is colored, but that can be bleached after the welding process. Nonsymmetrical squaraine dyes were prepared by condensation of squaric acid and two equivalents of various 3,5‐dimethoxy‐N,N‐dialkylanilines. After the incorporation into polyethylene and laser welding, the plastic was bleached either by heat treatment or by irradiation with a high pressure Xe‐lamp giving colorless polyethylene. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2245–2254
Electrochemically mediated atom transfer radical polymerization with dithiocarbamates as alkyl pseudohalides
Authors: Wang Yi , Fantin Marco , Matyjaszewski Krzysztof 
Published: September 2018

ABSTRACTElectrochemically mediated atom transfer radical polymerizations (ATRPs) provide well‐defined polymers with designed dispersity as well as under external temporal and spatial control. In this study, 1‐cyano‐1‐methylethyl diethyldithiocarbamate, typically used as chain‐transfer agent (CTA) in reversible addition–fragmentation chain transfer (RAFT) polymerization, was electrochemically activated by the ATRP catalyst CuI/2,2′‐bipyridine (bpy) to control the polymerization of methyl methacrylate. Mechanistic study showed that this polymerization was mainly controlled by the ATRP equilibrium. The effect of applied potential, catalyst counterion, catalyst concentration, and targeted degree of polymerization were investigated. The chain‐end functionality was preserved as demonstrated by chain extension of poly(methyl methacrylate) with n‐butyl methacrylate and styrene. This electrochemical ATRP procedure confirms that RAFT CTAs can be activated by an electrochemical stimulus. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 376–381
Oxidative stress‐induced structural changes in the microtubule‐associated flavoenzyme Irc15p from Saccharomyces cerevisiae
Authors: Koch Karin , Strandback Emilia , Jha Shalinee , Richter Gesa , Bourgeois Benjamin , Madl Tobias , Macheroux Peter 
Published: September 2018

AbstractThe genome of the yeast Saccharomyces cerevisiae encodes a canonical lipoamide dehydrogenase (Lpd1p) as part of the pyruvate dehydrogenase complex and a highly similar protein termed Irc15p (increased recombination centers 15). In contrast to Lpd1p, Irc15p lacks a pair of redox active cysteine residues required for the reduction of lipoamide and thus it is very unlikely that Irc15p performs a similar dithiol‐disulfide exchange reaction as reported for lipoamide dehydrogenases. We expressed IRC15 in Escherichia coli and purified the produced protein to conduct a detailed biochemical characterization. Here, we show that Irc15p is a dimeric protein with one FAD per protomer. Photoreduction of the protein generates the fully reduced hydroquinone without the occurrence of a flavin semiquinone radical. Similarly, reduction with NADH or NADPH yields the flavin hydroquinone without the occurrence of intermediates as observed for lipoamide dehydrogenase. The redox potential of Irc15p was −313 ± 1 mV and is thus similar to lipoamide dehydrogenase. Reduced Irc15p is oxidized by several artificial electron acceptors such as potassium ferricyanide, 2,6‐dichlorophenol‐indophenol, 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2H‐tetrazolium bromide, and menadione. However, disulfides such as cystine, glutathione, and lipoamide were unable to react with reduced Irc15p. Limited proteolysis and SAXS‐measurements revealed that the NADH‐dependent formation of hydrogen peroxide caused a substantial structural change in the dimeric protein. Therefore, we hypothesize that Irc15p undergoes a conformational change in the presence of elevated levels of hydrogen peroxide, which is a putative biomarker of oxidative stress. This conformational change may in turn modulate the interaction of Irc15p with other key players involved in regulating microtubule dynamics.
Isotonic concentrations of excipients control the dimerization rate of a therapeutic immunoglobulin G1 antibody during refrigerated storage based on their rank order of native‐state interaction
Authors: Banks Douglas D. , Cordia Jon F. , Spasojevic Vladimir , Sun Jeonghoon , Franc Sarah , Cho Younhee 
Published: September 2018

AbstractInert co‐solutes, or excipients, are often included in protein biologic formulations to adjust the tonicity of liquid dosage forms intended for subcutaneous delivery. Despite the low concentration of their use, many of these excipients alter protein–protein interactions such as dimerization and aggregation rates of high concentration monoclonal antibody (mAb) therapeutics to varying extents during long‐term refrigerated clinical storage, challenging the formulation scientist to make informed excipient selections at the earliest stages of development when protein supply and time are often limited. The objectives of this study were to better understand how isotonic concentrations of excipients influence the dimerization rates of a model mAb stored at refrigerated and room temperatures and explore protein sparing biophysical methods capable of predicting this dependence. Despite their prevalence of use in the biopharmaceutical industry, methods for assessing conformational stability such differential scanning calorimetry and isothermal equilibrium unfolding showed little predictive power and we highlight some of the assumptions and technical challenges of their use with mAbs. Conversely, measures of colloidal stability of the native‐state such as preferential interaction coefficients measured by vapor pressure osmometry and solubility assessed by polyethylene–glycol induced precipitation correlated reasonably well with the mAb dimerization data and are most consistent with the excipients tested minimizing dimerization by interacting favorably with the residues comprising the protein–protein association interface.
Photodissociation of phenol in the adiabatic representation: Tunneling, motions of phenyl ring, and kinetic isotope effects
Authors: He Ying , Zhao Huali , Wang Wenji 
Published: September 2018

AbstractThe photodissociation of phenol is a prototype of the photoinduced hydrogen detachment reaction. The dissociation rates of phenol through the excited S1 state are calculated with the quantum instanton method in full dimensionality. The Arrhenius plot of the rates shows that the quantum tunneling dominates the OH bond dissociation at low temperatures. The degrees of freedom of phenyl ring (C6H5) play extremely important roles in the dissociation of phenol. Fixing the phenyl ring at the equilibrium geometry can only provide reliable rates between 400 K and 800 K. The motions of phenyl ring have an impact on enhancing the dissociation by lowering the free energy barrier. The larger the amplitudes of the phenyl ring motions are, the more the free energy barrier will be reduced. The dissociation rates of C6H5OH are much larger than those of C6H5OD, which is due to the zero‐point energy and entropy effects.
Momentum space calculations of the binding energies of argon dimer
Authors: Sahraeian Taghi , Hadizadeh M. R. 
Published: September 2018

AbstractThe binding energies of argon dimer are calculated by solving the homogeneous Lippmann‐Schwinger integral equation in momentum space. Our numerical analysis using two models of argon‐argon interaction developed by Patkowski et al. not only confirms the eight argon dimer vibrational levels of the ground state of argon dimer (ie, for j = 0) predicted by other groups but also provides a very precise means for determining the binding energy of the ninth state which its value is a matter of discussion. Our calculations have been also extended to states with higher rotational quantum number j and we have calculated the energy of all 174 bound states for both potential models. Our numerical results for vibrational levels of the ground state of argon dimer are in excellent agreement with other theoretical calculations and available experimental data.
Engaging students in computational modeling: The role of an external audience in shaping conceptual learning, model quality, and classroom discourse
Authors: Pierson Ashlyn E. , Clark Douglas B. 
Published: September 2018

AbstractResearch suggests that designing for an external audience may support conceptual understanding by offering students increased opportunities to reframe perspectival thinking in ways that support domain‐specific reasoning. While this argument is theoretically compelling, to our knowledge, it has not been empirically tested in terms of comparing the conceptual growth of students designing computational models for an external audience to the conceptual growth of students designing computational models for a classroom audience of their teacher and peers. In a constructionist agent‐based computational modeling environment, we compare the conceptual understanding, artifact quality, and discourse of 6th grade students designing models of tides primarily for an external audience of younger students (i.e., designing for 5th graders) to the conceptual understanding of 6th grade students designing models for a classroom audience. We found that students who designed for an external audience of younger children displayed greater conceptual growth about the mechanisms that cause tidal bulges as evidenced by students’ pre–post assessments, models, and user guides/reports. Our analysis of classroom discourse suggests that designing for an audience of younger children may have facilitated domain‐specific reasoning in whole‐class discussions by creating opportunities for shifts between students’ own perspectives and the perspectives of their anticipated audience.