bluuebunny/crossref_metadata_2025_split huggingface dataset:
Correlation between tumor glucose metabolism and multiparametric functional MRI (IVIM and R2*) metrics in cervical carcinoma: Evidence from integrated 18F‐FDG PET/MR
Authors: Li‐Ou Zhang , Hong‐Zan Sun , Xiao‐Xi Bai , Zhong‐Wei Chen , Zai‐Ming Lu , Jun Xin , Qi‐Yong Guo 
Published: November 2018

BackgroundMultiparameter, multimodality 18F‐FDG PET/MRI holds great potential for the diagnosis of cervical cancer based on the correlation between tumor glucose metabolism and imaging parameters.PurposeTo characterize the heterogeneity of tumor glucose metabolism by evaluating the correlation between 18F‐FDG uptake parameters and multiparametric functional MRI metrics in cervical carcinoma.Study TypeRetrospective.PopulationFifty‐four patients with cervical carcinoma.Field Strength/SequenceHybrid PET/MR (3T), multi‐b DWI, and R2* mapping.AssessmentThe maximum and mean standardized uptake values (SUVmax and SUVmean, respectively) from PET and functional MRI metrics (D, D*, f, and R2*) were obtained. Cervical carcinoma tissues also underwent HIF‐1α, VEGF, and GLUT‐1 immunohistochemical staining.Statistical TestsSingle‐factor Spearman rank and Pearson correlation analysis and multiple linear regression (MLR) analysis were applied.ResultsR2*, D, and f have different degrees of correlation (moderate, weak, moderately strong correlation, respectively) with SUVmax and SUVmean (r = 0.530 and 0.527, and P < 0.001 for R2*; r = –0.292 and –0.291, and P < 0.05 for D; r = 0.539 and 0.520, and P < 0.001 for f, respectively). Immunohistochemical staining showed that HIF‐1α expression has a moderate degree of correlation with R2* (r = 0.491; P < 0.001); GLUT‐1 expression was significantly correlated with SUVmax and SUVmean (r = 0.633 and 0.622; P < 0.001), and VEGF expression had a moderately strong correlation with f (r = 0.457; P = 0.001). If SUVmax is the dependent variable, MLR yields an R‐squared value after adjustment (adjusted R‐squared) = 0.358, and F = 10.833 (P < 0.001), and the fitting linear equation is Y (SUVmax) = 9.184 + 0.161X1 (R2*)+50.343X2 (f)‐4.780 (D). Otherwise, MLR yields the adjusted R‐squared = 0.342, and F = 10.187 (P < 0.001), and the linear regression equation is Y (SUVmean) = 5.925 + 0.102X1 (R2*)+28.029X2 (f)‐2.907X3 (D).Data ConclusionThe functional MRI sequence parameters R2*, f, and D can provide information on the hypoxic condition, blood perfusion, and molecular diffusion of the tumor. 18F‐FDG PET/MR multi‐imaging technique can be adopted to evaluate the heterogeneity of glucose metabolism in cervical carcinoma.Level of Evidence: 3Technical Efficacy: Stage 3J. Magn. Reson. Imaging 2019;49:1704–1712.
Outcome of early dental implant placement versus other dental implant placement protocols: A systematic review and meta‐analysis
Authors: Bassir Seyed Hossein , El Kholy Karim , Chen Chia‐Yu , Lee Kyu Ha , Intini Giuseppe 
Published: November 2018

AbstractBackgroundThe aim of this systematic review and meta‐analysis was to compare the clinical efficacy of the early dental implant placement protocol with immediate and delayed dental implant placement protocols.MethodsAn electronic and manual search of literature was made to identify clinical studies comparing early implant placement with immediate or delayed placement. Data from the included studies were pooled and quantitative analyses were performed for the implant outcomes reported as the number of failed implants (primary outcome variable) and for changes in peri‐implant marginal bone level, peri‐implant probing depth, and peri‐implant soft tissue level (secondary outcome variables).ResultsTwelve studies met the inclusion criteria. Significant difference in risk of implant failure was found neither between the early and immediate placement protocols (risk difference = −0.018; 95% confidence interval [CI] = −0.06, 0.025; P = 0.416) nor between early and delayed placement protocols (risk difference = −0.008; 95% CI = –0.044, 0.028; P = 0.670). Pooled data of changes in peri‐implant marginal bone level demonstrated significantly less marginal bone loss for implants placed using the early placement protocol compared with those placed in fresh extraction sockets (P = 0.001; weighted mean difference = −0.14 mm; 95% CI = −0.22, −0.05). No significant differences were found between the protocols for the other variables.ConclusionsThe available evidence supports the clinical efficacy of the early implant placement protocol. Present findings indicate that the early implant placement protocol results in implant outcomes similar to immediate and delayed placement protocols and a superior stability of peri‐implant hard tissue compared with immediate implant placement.
The dependence of synchrony on timescale and geography in freshwater plankton
Authors: Anderson Thomas L. , Sheppard Lawrence W. , Walter Jonathan A. , Hendricks Susan P. , Levine Todd D. , White David S. , Reuman Daniel C. 
Published: November 2018

AbstractSpatial synchrony is defined by related fluctuations through time in population abundances measured at different locations. The degree of relatedness typically declines with increasing distance between sampling locations. Standard approaches for assessing synchrony assume isotropy in space and uniformity across timescales of analysis, but it is now known that spatial variability and timescale structure in population dynamics are common features. We tested for spatial and timescale structure in the patterns of synchrony of freshwater plankton in Kentucky Lake, U.S.A. We also evaluated whether different mechanisms may drive synchrony and its spatial structure on different timescales. Using wavelet techniques and matrix regression, we analyzed phytoplankton biomass and abundances of seven zooplankton taxa at 16 locations sampled from 1990 to 2015. We found that zooplankton abundances and phytoplankton biomass exhibited synchrony at multiple timescales. Timescale structure in the potential mechanisms of synchrony was revealed primarily through networks of relationships among zooplankton taxa, which differed by timescale. We found substantial interspecific variability in geographic structures of synchrony and their causes: all mechanisms we considered strongly explained geographic structure in synchrony for at least one species, while Euclidean distance between sampling locations was generally less well supported than more mechanistic explanations. Geographic structure in synchrony and its underlying mechanisms also depended on timescale for a minority of the taxa tested. Overall, our results show substantial and complex but interpretable variation in structures of synchrony across three variables: space, timescale, and taxon. It seems likely these aspects of synchrony are important general features of freshwater systems.
Sustained Protein Release from a Core‐Shell Drug Carrier System Comprised of Mesoporous Nanoparticles and an Injectable Hydrogel
Authors: Manavitehrani Iman , Fathi Ali , Schindeler Aaron , Dehghani Fariba 
Published: November 2018

AbstractThe manufacture of a biocompatible carrier for controlled delivery of bioactive compounds is described. This carrier is composed of a mesoporous silica nanoparticle as core that is homogenously distributed in an injectable hydrogel. For the synthesis of nanoparticles, a one step sol‐gel method is developed to produce pores with the range of 100 nm. BMP2 and Fluorescein‐conjugated bovine serum albumin is used as proteinaceous agents for measuring release, and is loaded into mesoporous silica nanoparticles at the optimum conditions of 48 h incubation period using 1:10 ratio of protein to nanoparticles. The release of proteins from either mesoporous nanoparticles or hydrogel individually involves a burst release stage, however the release from the core/shell carrier designed in this study follows a zero order kinetic. In summary, this biomaterial may be favorable for delivery of bioactive compounds such as BMP2 for a range of applications including bone tissue regeneration.
Extremely Soft, Conductive, and Transparent Ionic Gels by 3D Optical Printing
Authors: Ahmed Kumkum , Naga Naofumi , Kawakami Masaru , Furukawa Hidemitsu 
Published: November 2018

AbstractA series of 3D printable multifunctional ionic gels (IGs) are developed incorporating ionic liquid (IL) in the thiol–ene network of thiol‐based end‐crosslinker and acrylate monomers. The resulted gels, termed as thiol‐ionic gels (T‐IGs), are highly transparent and very soft with IL content of 70–85 wt%. The mechanical and conductive properties of the T‐IGs are found to be largely dependent on the IL content, end‐crosslinker functionalities, and chain‐length of monomers. Progression of ionic conductivity is observed with an increase in IL content and conductivity as high as 5.40 mS cm−1is attained for longer acrylate group containing T‐IGs at room temperature, while further increase is observed at elevated temperature. T‐IGs in all systems are found to exhibit superior thermal stability. Three‐dimensional fabrication of these functional T‐IGs is achieved by optical 3D printing process with microscale resolution in facile steps.
Functional Macromolecular Systems: Kinetic Pathways to Obtain Tailored Structures
Authors: Abetz Volker , Kremer Kurt , Müller Marcus , Reiter Günter 
Published: November 2018

AbstractThis article aims to stimulate research on non‐equilibrium macromolecular systems, as nowadays a large toolbox to synthesize tailored macromolecules is available. A large variety of characterization methods covering a broad spectrum of length and timescales allows researchers to follow and also manipulate macromolecular systems on their paths toward equilibrium. These possibilities are paralleled by the development of new concepts of the statistical physics of non‐equilibrium phenomena in macromolecular systems as well as new models and algorithms for computer simulation.
Multilayered Polyurethane–Hydroxyapatite Composite for Meniscus Replacements
Authors: Song Eun‐Ho , Seong Yun‐Jeong , Kim Jinyoung , Kim Hyoun‐Ee , Jeong Seol‐Ha 
Published: November 2018

AbstractInspired by the anisotropic structure of natural menisci, porous and densified layers of glycerol phosphate (gp)‐conjugated polyurethane (PU) and hydroxyapatite (HA), abbreviated PUH, are alternately stacked to fabricate a biomimetic multilayered scaffold. Densification is used to better match the mechanical properties of the composites to those of natural menisci for load‐bearing applications. The porosity is easily controlled (30%, 10%, and 7%) during the densification process by adjusting the applied heat and pressure. The strength and elastic modulus of the densified PUH are significantly higher than those of the porous PUH because HA is trapped as fillers inside the densified PU matrix. Multi‐layered PUH is successfully fabricated after stacking the densified and porous layers alternately. And each layer is highly attached, resulting in good interfacial stability. In addition, the scaffold is stiff along thex‐ andy‐directions and more flexible along thez‐axis (the stacking direction), as designed.
Optimized Diffusion‐Weighting Gradient Waveform Design (ODGD) formulation for motion compensation and concomitant gradient nulling
Authors: Peña‐Nogales Óscar , Zhang Yuxin , Wang Xiaoke , de Luis‐Garcia Rodrigo , Aja‐Fernández Santiago , Holmes James H. , Hernando Diego 
Published: November 2018

PurposeTo present a novel Optimized Diffusion‐weighting Gradient waveform Design (ODGD) method for the design of minimum echo time (TE), bulk motion‐compensated, and concomitant gradient (CG)‐nulling waveforms for diffusion MRI.MethodsODGD motion‐compensated waveforms were designed for various moment‐nullings Mn (n = 0, 1, 2), for a range of b‐values, and spatial resolutions, both without (ODGD‐Mn) and with CG‐nulling (ODGD‐Mn‐CG). Phantom and in‐vivo (brain and liver) experiments were conducted with various ODGD waveforms to compare motion robustness, signal‐to‐noise ratio (SNR), and apparent diffusion coefficient (ADC) maps with state‐of‐the‐art waveforms.ResultsODGD‐Mn and ODGD‐Mn‐CG waveforms reduced the TE of state‐of‐the‐art waveforms. This TE reduction resulted in significantly higher SNR (P < 0.05) in both phantom and in‐vivo experiments. ODGD‐M1 improved the SNR of BIPOLAR (42.8 ± 5.3 vs. 32.9 ± 3.3) in the brain, and ODGD‐M2 the SNR of motion‐compensated (MOCO) and Convex Optimized Diffusion Encoding‐M2 (CODE‐M2) (12.3 ± 3.6 vs. 9.7 ± 2.9 and 10.2 ± 3.4, respectively) in the liver. Further, ODGD‐M2 also showed excellent motion robustness in the liver. ODGD‐Mn‐CG waveforms reduced the CG‐related dephasing effects of non CG‐nulling waveforms in phantom and in‐vivo experiments, resulting in accurate ADC maps.ConclusionsODGD waveforms enable motion‐robust diffusion MRI with reduced TEs, increased SNR, and reduced ADC bias compared to state‐of‐the‐art waveforms in theoretical results, simulations, phantoms and in‐vivo experiments.
Realistic 4D MRI abdominal phantom for the evaluation and comparison of acquisition and reconstruction techniques
Authors: Lo Wei‐Ching , Chen Yong , Jiang Yun , Hamilton Jesse , Grimm Robert , Griswold Mark , Gulani Vikas , Seiberlich Nicole 
Published: November 2018

PurposeThis work presents a 4D numerical abdominal phantom, which includes T1 and T2 relaxation times, proton density fat fraction, perfusion, and diffusion, as well as respiratory motion for the evaluation and comparison of acquisition and reconstruction techniques.MethodsThe 3D anatomical mesh models were non‐rigidly scaled and shifted by respiratory motion derived from an in vivo scan. A time series of voxelized 3D abdominal phantom images were obtained with contrast determined by the tissue properties and pulse sequence parameters. Two example simulations: (1) 3D T1 mapping under breath‐hold and free‐breathing acquisition conditions and (2) two different reconstruction techniques for accelerated 3D dynamic contrast‐enhanced MRI, are presented. The source codes can be found at https://github.com/SeiberlichLab/Abdominal_MR_Phantom.ResultsThe proposed 4D abdominal phantom can successfully simulate images and MRI data with nonrigid respiratory motion and specific contrast settings and data sampling schemes. In example 1, the use of a numerical 4D abdominal phantom was demonstrated to aid in the comparison between different approaches for volumetric T1 mapping. In example 2, the average arterial fraction over the healthy hepatic parenchyma as calculated with spiral generalized autocalibrating partial parallel acquisition was closer to that from the fully sampled data than the arterial fraction from conjugate gradient sensitivity encoding, although both are elevated compared to the gold‐standard reference.ConclusionThis realistic abdominal MR phantom can be used to simulate different pulse sequences and data sampling schemes for the comparison of acquisition and reconstruction methods under controlled conditions that are impossible or prohibitively difficult to perform in vivo.
Optimization of phase‐contrast MRI for the estimation of global cerebral blood flow of mice at 11.7T
Authors: Wei Zhiliang , Chen Lin , Lin Zixuan , Jiang Dengrong , Xu Jiadi , Liu Peiying , van Zijl Peter C.M. , Lu Hanzhang 
Published: November 2018

PurposeTo optimize phase‐contrast (PC) MRI for the measurement of global cerebral blood flow (CBF) in the mouse at 11.7T.MethodsWe determined proper velocity encoding (VENC) for internal carotid arteries (ICAs) and vertebral arteries (VAs). Next, we optimized spatial resolution of the sequence. To shorten scan time without compromising data quality, we further optimized repetition time and developed a reduced field‐of‐view (FOV) scheme for ICA and VA PC MRI. Whole‐brain volume was determined with T2‐weighted image to obtain unit‐volume CBF.ResultsPeak flow velocities were 13.8 ± 1.7, 14.4 ± 0.6, 6.5 ± 1.7, and 6.7 ± 1.3 cm/s for left ICA, right ICA, left VA, and right VA, respectively. Thus, VENC values of 20 and 10 cm/s were chosen for ICA and VA PC MRI, respectively. An in‐plane spatial resolution of 50 × 50 μm2 was found to provide a reasonable trade‐off between reducing partial‐volume effects and maintaining signal‐to‐noise ratio. Because of the fact that saturated spins in the imaging slice are rapidly replaced by fresh spins, TR of the sequence can be decreased to as short as 15 ms without reducing signal intensity, thereby substantially lowering scan time. Moreover, reduced FOV along the phase‐encoding direction was able to shorten scan time by 33.3% while maintaining measurement accuracy. With these optimizations, it took 96 seconds to evaluate CBF with a test‐retest variability of approximately 5% and an inter‐rater correlation of >0.95. Global unit‐volume CBF was found to be 279.5 ± 11.1 mL of blood/100 ml of tissue/min.ConclusionWe have optimized PC MRI for noninvasive quantification of blood flow in mice at 11.7T.
An equilibrium‐based stress recovery procedure for the VEM
Authors: Artioli E. , de Miranda S. , Lovadina C. , Patruno L. 
Published: November 2018

SummaryWithin the framework of the displacement‐based virtual element method (VEM), namely, for plane elasticity, an important topic is the development of optimal techniques for the evaluation of the stress field. In fact, in the classical VEM formulation, the same projection operator used to approximate the strain field (and then evaluate the stiffness matrix) is employed to recover, via constitutive law, the stress field. Considering a first‐order formulation, strains are locally mapped onto constant functions, and stresses are piecewise constant. However, the virtual displacements might engender more complex strain fields for polygons, which are not triangles. This leads to an undesirable loss of information with respect to the underlying virtual stress field. The recovery by compatibility in patches, originally proposed for finite element schemes, is here extended to VEM, aiming at mitigating such an effect. Stresses are recovered by minimizing the complementary energy of patches of elements over an assumed set of equilibrated stress modes. The procedure is simple, efficient, and can be readily implemented in existing codes. Numerical tests confirm the good performance of the proposed technique in terms of accuracy and indicate an increase of convergence rate with respect to the classical approach in many cases.
Inverse mass matrix for isogeometric explicit transient analysis via the method of localized Lagrange multipliers
Authors: González José A. , Kopačka J. , Kolman R. , Cho S. S. , Park K. C. 
Published: November 2018

AbstractA variational framework is employed to generate inverse mass matrices for isogeometric analysis (IGA). As different dual bases impact not only accuracy but also computational overhead, several dual bases are extensively investigated. Specifically, locally discontinuous biorthogonal basis functions are evaluated in detail for B‐splines of high continuity and Bézier elements with a standard C0 continuous finite element structure. The boundary conditions are enforced by the method of localized Lagrangian multipliers after generating the inverse mass matrix for completely free body. Thus, unlike inverse mass matrix methods without employing the method of Lagrange multipliers, no modifications in the reciprocal basis functions are needed to account for the boundary conditions. Hence, the present method does not require internal modifications of existing IGA software structures. Numerical examples show that globally continuous dual basis functions yield better accuracy than locally discontinuous biorthogonal functions, but with much higher computational overhead. Locally discontinuous dual basis functions are found to be an economical alternative to lumped mass matrices when combined with mass parameterization. The resulting inverse mass matrices are tested in several vibration problems and applied to explicit transient analysis of structures.
Synthesis of Metallomacrocycle and Coordination Polymers with Pyridine‐Based Amidocarboxylate Ligands and Their Catalytic Activities towards the Henry and Knoevenagel Reactions
Authors: Karmakar Anirban , Rúbio Guilherme M. D. M. , Guedes da Silva M. Fátima C. , Pombeiro Armando J. L. 
Published: November 2018

AbstractThe reactions of 3,3′‐{(pyridine‐2,6‐dicarbonyl)bis(azanediyl)}dibenzoic acid (H2L) with zinc(II), cadmium(II), and samarium(III) nitrates were studied, and the obtained compounds, [Zn(1κO:2κO′‐L)(H2O)2]n (1), [Cd(1κO2:2κO2‐L)(H2O)2]2⋅6n H2O⋅ n C4H8O2⋅1.5n DMF (2), and [Sm(1κO:2κO′O′′:3κO′′′‐L)(NO3)(H2O)(dmf)]n⋅n DMF (3), were characterized by elemental analysis, FTIR spectroscopy, thermogravimetric analysis, and X‐ray single‐crystal diffraction. Compounds 1 and 3 have 1D zigzag‐ and double‐chain‐type structures, respectively, whereas 2 features a dinuclear metallomacrocyclic complex. The ligand (L2−) orients in different conformations, that is, syn‐syn for 1 and anti‐anti for 2 and 3. Compound 1 is the first example in which the syn‐syn conformation for this ligand has been observed. These compounds act as heterogeneous catalysts for the nitroaldol (Henry; in water medium) and Knoevenagel condensation reactions of different aldehydes, and the most effective is zinc coordination polymer 1. Recyclability, heterogeneity, and size‐selectivity tests were performed, which showed that the catalyst was highly active over at least four recycling runs.
Water‐Based Synthesis of Hydrophobic Ionic Liquids [N8888][oleate] and [P666,14][oleate] and their Bioprocess Compatibility
Authors: Raes Sanne M. T. , Jourdin Ludovic , Carlucci Livio , van den Bruinhorst Adriaan , Strik David P. B. T. B. , Buisman Cees J. N. 
Published: November 2018

AbstractThe conversion of organic waste streams into carboxylic acids as renewable feedstocks results in relatively dilute aqueous streams. Carboxylic acids can be recovered from such streams by using liquid–liquid extraction. Hydrophobic ionic liquids (ILs) are novel extractants that can be used for carboxylic acid recovery. To integrate these ILs as in situ extractants in several biotechnological applications, the IL must be compatible with the bioprocesses. Herein the ILs [P666,14][oleate] and [N8888][oleate] were synthesized in water and their bioprocess compatibility was assessed by temporary exposure to an aqueous phase that contained methanogenic granular sludge. After transfer of the sludge into fresh medium, [P666,14][oleate]‐exposed granules were completely inhibited. Granules exposed to [N8888][oleate] sustained anaerobic digestion activity, albeit moderately reduced. The IL contaminants, bromide (5–500 ppm) and oleate (10–4000 ppm), were shown not to inhibit the methanogenic conversion of acetate. [P666,14] was identified as a bioprocess‐incompatible component. However, our results showed that [N8888][oleate] was bioprocess compatible and, therefore, has potential applications in bioprocesses.
Influence of phosphorus‐grafted expandable graphite on the flame‐retardant property of UHMWPE composite
Authors: Wang Huaming , Cao Jingshi , Cao Changlin , Guo Yiyou , Luo Fubin , Qian Qingrong , Huang Baoquan , Xiao Liren , Chen Qinghua 
Published: November 2018

In this paper, an efficient flame retardant, 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) was covalently grafted onto the surface of expandable graphite (EG). The resultant DOPO‐grafted expandable graphite (EG‐g‐DOPO) was characterized by Fourier transform infrared spectroscopy, energy dispersive spectroscopy, and X‐ray photoelectron spectroscopy (XPS), respectively. The thermal stability of EG‐g‐DOPO was also evaluated by thermogravimetric analysis (TGA). Moreover, a series of flame‐retardant ultra‐high‐molecular‐weight polyethylene (UHMWPE) composites with various concentrations of EG‐g‐DOPO were prepared and evaluated. The results show that the UHMWPE composite with 20 wt% EG‐g‐DOPO possesses a satisfactory UL‐94 flame‐retardant grade (V‐0) and a high limiting oxygen index (30.6%). The residual char of the UHMWPE composite with higher EG‐g‐DOPO concentration shows more compact and integrated, providing an efficient barrier for heat release.