bluuebunny/crossref_metadata_2025_split huggingface dataset:
Potential of a statistical approach for the standardization of multicenter diffusion tensor data: A phantom study
Authors: Timmermans Charlotte , Smeets Dirk , Verheyden Jan , Terzopoulos Vasilis , Anania Vincenzo , Parizel Paul M. , Maas Andrew 
Published: January 2019

BackgroundDiffusion tensor imaging (DTI) parameters, such as fractional anisotropy (FA), allow examining the structural integrity of the brain. However, the true value of these parameters may be confounded by variability in MR hardware, acquisition parameters, and image quality.PurposeTo examine the effects of confounding factors on FA and to evaluate the feasibility of statistical methods to model and reduce multicenter variability.Study TypeLongitudinal multicenter study.PhantomDTI single strand phantom (HQ imaging).Field Strength/Sequence3T diffusion tensor imaging.AssessmentsThirteen European imaging centers participated. DTI scans were acquired every 6 months and whenever maintenance or upgrades to the system were performed. A total of 64 scans were acquired in 2 years, obtained by three scanner vendors, using six individual head coils, and 12 software versions.Statistical TestsThe variability in FA was assessed by the coefficients of variation (CoV). Several linear mixed effects models (LMEM) were developed and compared by means of the Akaike Information Criterion (AIC).ResultsThe CoV was 2.22% for mean FA and 18.40% for standard deviation of FA. The variables “site” (P = 9.26 × 10−5), “vendor” (P = 2.18 × 10−5), “head coil” (P = 9.00 × 10−4), “scanner drift,” “bandwidth” (P = 0.033), “TE” (P = 8.20 × 10−6), “SNR” (P = 0.029) and “mean residuals” (P = 6.50 × 10−4) had a significant effect on the variability in mean FA. The variables “site” (P = 4.00 × 10−4), “head coil” (P = 2.00 × 10−4), “software” (P = 0.014), and “mean voxel outlier intensity count” (P = 1.10 × 10−4) had a significant effect on the variability in standard deviation of FA. The mean FA was best predicted by an LMEM that included “vendor” and the interaction term of “SNR” and “head coil” as model factors (AIC –347.98). In contrast, the standard deviation of FA was best predicted by an LMEM that included “vendor,” “bandwidth,” “TE,” and the interaction term between “SNR” and “head coil” (AIC –399.81).Data ConclusionOur findings suggest that perhaps statistical models seem promising to model the variability in quantitative DTI biomarkers for clinical routine and multicenter studies.Level of Evidence: 4Technical Efficacy: Stage 2J. Magn. Reson. Imaging 2019;49:955–965.
Symmetries of modes in Ni3V2O8: Polarized Raman spectroscopy and ab initio phonon calculations
Authors: Kesari Swayam , Rao Rekha , Gupta Mayanak K. , Mittal R. , Balakrishnan Geetha 
Published: January 2019

AbstractKnowledge of symmetries of vibrational modes is essential for understanding the mechanism of structural transitions and spin‐phonon coupling in multiferroics where phonons play a vital role. Using polarized Raman spectroscopy, we have identified and assigned symmetries of 30 out of the 36 expected Raman active modes in Ni3V2O8. The zone‐centred phonon mode wavenumbers are calculated using ab initio calculations. The gerade mode wavenumbers are compared with our polarized Raman data whereas ungerade mode wavenumbers are compared with the reported infrared measurements and a good agreement was observed between the experimentally measured wavenumbers and the calculated wavenumbers. The displacements of different types of vibrations calculated and visualized using ab initio phonon calculation are presented. These assignments will be useful for visualization of Raman modes that may be sensitive to different magnetic states and to explore spin–lattice coupling across magnetic transitions.
Capillary electrophoresis for the analysis of antidepressant drugs: A review
Authors: Abdul Keyon Aemi Syazwani , Miskam Mazidatulakmam , Ishak Nur Syazwani , Mahat Naji Arafat , Mohamed Huri Mohamad Afiq , Abdul Wahab Roswanira , Chandren Sheela , Abdul Razak Fazira Ilyana , Ng Nyuk‐Ting , Ali Timothy Gandu 
Published: January 2019

AbstractDepression is a common mental disorder that may lead to major mental health problems, and antidepressant drugs have been used as a treatment of choice to mitigate symptoms of major depressive disorders by ameliorating the chemical imbalances of neurotransmitters in brain. Since abusing antidepressant drugs such as selective serotonin reuptake inhibitors and tricyclic antidepressant drugs can cause severe adverse effects, continuous toxicological monitoring of the parent compounds as well as their metabolites using numerous analytical methods appears pertinent. Among them, capillary electrophoresis has been popularly utilized since the method has a lot of advantages viz. using small amounts of sample and solvents, ease of operation, and rapid analysis. This review paper brings a survey of more than 30 papers on capillary electrophoresis of antidepressant drugs published approximately from 1999 until 2018. It focuses on the reported capillary electrophoresis techniques and their applications and challenges for determining antidepressant drugs and their metabolites. It is organized according to the commonly used capillary zone electrophoresis method, followed by non‐aqueous capillary electrophoresis and micellar electrokinetic chromatography, with details on breakthrough findings. Where available, information is given about the background electrolyte used, detector utilized, and sensitivity obtained.
A Comparison of the Behavior of Monomolecular and Dual Molecular Probes in F127/Cyclodextrin Systems
Authors: Baratoiu Rodica , Mocanu Sorin , Matei Iulia , Bem Marioara , Hristea Elena , Tecuceanu Victorita , Ionita Gabriela 
Published: January 2019

AbstractMolecular probes are often used to describe local interactions and to characterize inhomogeneities in complex systems. In this study, two series of monomolecular probes (paramagnetic or fluorescent) and a series of dual molecular probes are used to evaluate local changes and the regions targeted by these probes in three pluronic F127 systems, in the absence and in the presence of 2‐hydroxypropyl‐β‐cyclodextrin, which have been previously characterized. All molecular probes used in this study have as a common structural unit the short oligoethylene chains that link (2,2,6,6‐Tetramethylpiperidin‐1‐yl)oxyl (TEMPO) and/or pyrene moieties. Using these probes, changes in hydrophobicity inside the pluronic micelles are evidenced and the micelle‐to‐gel phase transition is characterized.
Widely tunable single bandpass microwave photonic filter based on dual‐fiber stimulated Brillouin scattering
Authors: Yan Juanjuan , Li Liwei , Yi Xiaoke , Chew Suen X. 
Published: January 2019

AbstractA new technique to achieve a single bandpass microwave photonic filter (MPF) with wide tunability based on stimulated Brillouin scattering is proposed. The MPF cascades the Brillouin frequency shifter and amplification based on a dual‐fiber structure. The experimental results present a single bandpass MPF located at 21.4 GHz with a 3‐dB bandwidth of 38 MHz and an out‐of‐band rejection ratio over 30 dB. The proposed single bandpass MPF also successfully demonstrates a wide‐band tuning over 40 GHz, which is achieved by employing a frequency shifter based on carrier suppressed single‐sideband modulation scheme in the structure.
Application of proton field‐cyclingNMRrelaxometry for studying translational diffusion in simple liquids and polymer melts
Authors: Flämig Max , Hofmann Marius , Lichtinger Anne , Rössler Ernst A. 
Published: January 2019

AbstractWith the availability of commercial field‐cycling relaxometers together with progress of home‐built instruments nuclear magnetic resonance relaxometry has gained new momentum as a method of investigating the dynamics in viscous liquids and polymer melts. The method provides the frequency dependence of the spin–lattice relaxation rate. In the case of protons, one distinguishes intramolecular and intermolecular relaxation pathways. Whereas the intramolecular contribution prevails at high frequencies and reflects rotational dynamics, the often ignored intermolecular relaxation contribution dominates at low‐frequency and provides access to translational dynamics. A universal low‐frequencies dispersion law holds which in pure systems allows determining the diffusion coefficient in a straightforward way. In addition, the rotational time constant is extracted from the high‐frequency relaxation contribution. This is demonstrated for simple and ionic liquids and for polymer melts.
A theoretical NMR study of polymorphism in crystal structures of azoles and benzazoles
Authors: Marín‐Luna Marta , Claramunt Rosa M. , Nieto Carla I. , Alkorta Ibon , Elguero José , Reviriego Felipe 
Published: January 2019

AbstractThe NMR chemical shifts of two azoles and one benzazole whose crystal structures present polymorphism have been computed using the GIPAW approach. 15N and 13C nuclei have been studied. Statistical analysis of the computed 13C and 15N chemical shifts indicates that the GIPAW chemical shifts reproduce with a high degree of accuracy those experimentally reported. This methodology can be used to identify other polymorphic crystal structures.
In situ measurement of deposit layer formation during skim milk filtration by MRI
Authors: Schork Nicolas , Schuhmann Sebastian , Nirschl Hermann , Guthausen Gisela 
Published: January 2019

AbstractFiltration and separation via membranes are key processes in food processing. One major application of membrane filtration is in the dairy industry, aiming for the separation of different milk proteins. The various chemical components of milk possess different physiochemical properties and can be used most effectively in food processing if they are separately available and remain in their native state. Microfiltration of skim milk allows a fractionation of the milk proteins casein and whey by size. A deposit is formed on the membrane surface mainly but not exclusively by micellar casein proteins during filtration. Membrane pore blockage by whey proteins and fouling occur during membrane filtration, negatively affecting the yield of the whey protein fraction. Skim milk filtration and the deposit layer formation were measured time and spatially resolved by in situ magnetic resonance imaging (MRI). The nature of the fouling layer was investigated during dead‐end filtration in ceramic hollow fiber membranes. MRI was used to further clarify the influence of operating conditions on separation and filtration mechanisms that are responsible for growth of the fouling layer and its reversibility. The MRI measurements were analyzed for a detailed description of skim milk filtration by modeling the signal intensity distribution.
Calculations of 13C NMR chemical shifts and F–C coupling constants of ciprofloxacin
Authors: Koch Andreas , Stamboliyska Bistra , Mikhova Bozhana , Breznica‐Selmani Pranvera , Mladenovska Kristina , Popovski Emil 
Published: January 2019

AbstractCiprofloxacin is a widely used fluoroquinolone antibiotic. In this work, a comprehensive evaluation of MP2 and DFT with different functionals and basis sets was carried out to select the most suitable level of theory for the study of the NMR properties of ciprofloxacin. Their relative predictive capabilities were evaluated comparing the theoretically predicted and experimental spectral data. Our computational results indicated that in contrast to the solid state, the molecule of ciprofloxacin does not exist as a zwitterion in gaseous state. The results of the calculations of the chemical shifts most close to the experimental were obtained with B3LYP/aug‐cc‐pVDZ. The F–C coupling constants were calculated systematically with different DFT methods and several basis sets. In general, the calculations of the coupling constants with the BHandH computational method including the applied in this work 6‐311++G**, EPRII, and EPRIII basis sets showed a good reproducibility of the experimental values of the coupling constants.
A multiobjective topology optimization approach for cost and time minimization in additive manufacturing
Authors: Ryan Luke , Kim Il Yong 
Published: January 2019

SummaryThe ever‐present drive for increasingly high‐performance designs realized on shorter timelines has fostered the need for computational design generation tools such as topology optimization. However, topology optimization has always posed the challenge of generating difficult, if not impossible to manufacture designs. The recent proliferation of additive manufacturing technologies provides a solution to this challenge. The integration of these technologies undoubtedly has the potential for significant impact in the world of mechanical design and engineering. This work presents a new methodology which mathematically considers additive manufacturing cost and build time alongside the structural performance of a component during the topology optimization procedure. Two geometric factors, namely, the surface area and support volume required for the design, are found to correlate to cost and build time and are controlled through the topology optimization procedure. A novel methodology to consider each of these factors dynamically during the topology optimization procedure is presented. The methodology, based largely on the use of the spatial gradient of the density field, is developed in such a way that it does not leverage the finite element discretization scheme. This work investigates a problem that has not yet been explored in the literature: direct minimization of support material volume in density‐based topology optimization. The entire methodology is formulated in a smooth and differentiable manner, and the sensitivity expressions required by gradient based optimization solvers are presented. A series of example problems are provided to demonstrate the efficacy of the proposed methodology.
Determination of lamotrigine in human plasma using liquid chromatography‐tandem mass spectrometry
Authors: Itabashi Shogo , Bito Rina , Nishina Maika , Fukumoto Maki , Soda Midori , Doi Mitsunori , Usui Shigeyuki , Kitaichi Kiyoyuki 
Published: January 2019

AbstractAimLamotrigine (LTG) is a widely used anti‐epileptic drug that is administered to avoid seizures and to maintain seizure‐free status. However, several factors reportedly cause individual differences of plasma LTG levels, and the therapeutic target range of LTG varies between individuals. Thus, to optimize effective doses of LTG, we developed a rapid and simple method for determining plasma LTG concentrations.MethodsLamotrigine and the internal standard papaverine were extracted from human plasma using solid‐phase extraction. After filtration, 5‐μL aliquots of final samples were injected into the liquid chromatography‐tandem mass spectrometry instrument and LTG and internal standard were separated using a CadenzaCD‐C18 column (100 × 2 mm, 3 μm) with 0.1% formic acid in water/acetonitrile (2/1, v/v).ResultsThe calibration curve was linear from 0.2 to 5.0 μg/mL, and assessments of recovery, intra‐ and inter‐day precision and accuracy, matrix effects, freeze and thaw stability, and long‐term stability demonstrated good reproducibility. Retention times of LTG and internal standard were 1.6 and 2.0 minutes, respectively, and the total run time was 3.5 minutes for each sample.ConclusionWe developed a rapid and simple method for determining plasma LTG concentrations. The present novel system could be used to inform LTG dose adjustments for individual patients.
General anesthesia, conscious sedation, or nothing: Decision‐making by children during painful procedures
Authors: Maslak Karolina , Favara‐Scacco Cinzia , Barchitta Martina , Agodi Antonella , Astuto Marinella , Scalisi Rita , Italia Simona , Bellia Francesco , Bertuna Gregoria , D'Amico Salvatore , La Spina Milena , Licciardello Maria , Lo Nigro Luca , Samperi Piera , Miraglia Vito , Cannata Emanuela , Meli Mariaclaudia , Puglisi Federica , Parisi Giuseppe Fabio , Russo Giovanna , Di Cataldo Andrea 
Published: January 2019

AbstractBackgroundFollowing diagnosis, children with cancer suddenly find themselves in an unknown world where unfamiliar adults make all the important decisions. Children typically experience increasing levels of anxiety with repeated invasive procedures and do not adapt to the discomfort. The aim of the present study is to explore the possibility of asking children directly about their medical support preferences during invasive procedures.ProcedureEach patient was offered a choice of medical support on the day of the procedure, specifically general anesthesia (GA), conscious sedation (CS), or nothing. An ad hoc assessment tool was prepared in order to measure child discomfort before, during, and after each procedure, and caregiver adequacy was measured. Both instruments were completed at each procedure by the attending psychologist.ResultsWe monitored 247 consecutive invasive procedures in 85 children and found that children in the 4 to 7 year age group showed significantly higher distress levels. GA was chosen 66 times (26.7%), CS was chosen 97 times (39.3%), and nothing was chosen 5 times and exclusively by adolescents. The child did not choose in 79 procedures (32%). The selection of medical support differed between age groups and distress level was reduced at succeeding procedures.ConclusionsOffering children the choice of medical support during invasive procedures allows for tailored support based on individual needs and is an effective modality to return active control to young patients, limiting the emotional trauma of cancer and treatment.
(E)‐3‐X‐indoline‐2‐ones as potent and selective inhibitors against different receptor tyrosine kinase (RTKs) in solution vs gas phase, at DFT
Authors: Soleimani‐Amiri S. , Koohi M. 
Published: January 2019

AbstractUsing DFT SCRF calculations, we have evaluated the solvent effects on the structure, stability, and electronic properties of biologically active compounds as (E)‐3‐X‐indoline‐2‐one derivatives (X = phenyl, furan‐2‐yl, 1H‐pyrrol‐2‐yl, and thiophen‐2‐yl, I‐IV, respectively) in six solvents. These solvents differ in their polarity with the dielectric constants varying from 2.2 to 78.5 including benzene, C2H4Cl2, EtOH, H2O, nitromethane, and DMSO. Moreover, two of them have a hydrogen‐bond donor character. All possible hydrogen‐bonding in the water solution with oxygen and nitrogen atoms as hydrogen‐acceptor centers in indoline‐2‐ones derivatives, I‐IV, have been considered in our studies. The stability of each solute (I‐IV) depends on the dielectric constant of the solvent and the possibility of the hydrogen bonding. Moreover, the highest observed solvent‐gas phase energy gaps (∆Es‐g) relate to structure III in water, whereas the lowest ∆Es‐g is associated with II in benzene. Thus, III is the most solvent sensitive and enjoys maximum stabilization in water. On the other extreme, II is the least solvent sensitive, and its stability is the least affected by salvation in benzene. Forbidden concerted [1,6] and [1,3]‐H shift mechanisms are suggested for the ketone III―III′, III′′ enole tautomerizations in gas phase, while allowed step‐by‐step [1,6] and [1,3]‐H shifts are proposed for tautomerization in water.
Extending the human capital model of migration: The role of risk, place, and social capital in the migration decision
Authors: Clark William A.V. , Lisowski William 
Published: January 2019

AbstractMigration is both an economic and an emotional decision; it breaks ties and requires a fundamental commitment to changed workplaces, new social networks and relationships, and new residential environments. Although economic returns matter in the decision to move, it is clear from survey studies that many moves are more complex than those built around market incentives alone. To explore the decision‐making underlying mobility and to evaluate why some decisions are deferred, we explore the ideas of prospect theory, endowment effects, and social capital as new ways to understand the decision‐making process about migrating. Often, the focus on migration passes over the associated and important question of when and why individuals and families do not move. By considering the intersecting roles of risk aversion, place attachment, and social capital, we can use these ideas to model the decision to move and show that both endowment and social capital play important roles in the migratory decision. Our findings extend previous research by incorporating both endowment and social capital in the models of migration.
Synthesis, Antitubercular and Antimicrobial Activity of 1,2,4‐Triazolidine‐3‐thione Functionalized Coumarin and Phenyl Derivatives and Molecular Docking Studies
Authors: Shaikh Farzanabi , Shastri Samundeeswari L. , Naik Nirmala S. , Kulkarni Rashmi , Madar Jyoti M. , Shastri Lokesh A. , Joshi Shrinivas D. , Sunagar Vinay 
Published: January 2019

AbstractTuberculosis (TB) is still a demanding worldwide health problem and mycobacterium tuberculosis (MTB) remains one of the most toxic human pathogens. In pursuit of searching new antitubercular and antimicrobial agents, substituted coumarin and phenyl‐1,2,4‐triazolidine‐3‐thiones 4a‐i and 5a‐e have been synthesized and evaluated for their antitubercular and antimicrobial activities. Most of the Substituted coumarin and phenyl‐1,2,4‐triazolidine‐3‐thiones showed promising activity against Mycobacterium tuberculosis (H37Rv). The title compounds have exhibited excellent in vitro antibacterial activity against the S.aureus, Bacillus sps and E.coli with the values of low MIC ranging from of 0.4 to 1.6 μg/mL. In vitro antifungal activity shown that the compounds 4a‐i and 5a‐e are excellent antifungal agents against Candida albicans, Aspergillus flavus, Aspergillus niger and Aspergillus fumigate fungal stains with the values of low minimum inhibitory concentrations (MIC) ranging from 0.4 to 6.25 μg/mL. Molecular docking study was performed for all the synthesized compounds with E.coli as antibacterial and Mycobacterium tuberculosis DprE1 as antituberculosis.
Ultrasonication‐Assisted Synthesis of 3‐Substituted Indoles in Water Using Polymer Grafted ZnO Nanoparticles as Eco‐Friendly Catalyst
Authors: Shaikh Tauhid , Sharma Anuj , Kaur Harjinder 
Published: January 2019

AbstractIndole based heterocyclic molecules are important and valuable structural unit that are present in various biologically active natural products, pharmaceuticals and agrochemicals. In this paper, zinc oxide nanoparticles were explored as catalyst for the synthesis of 3‐substituted indoles in water via ultra‐sonication. The stability of ZnO nanoparticles and their dispersion in water was enhanced by grafting it with a biodegradable polymer (poly lactic acid). The proposed methodology is capable of providing desired products in good yield (83‐97%) and 25 derivatives of indoles were synthesized. The green reaction metrics such as E‐factor (0.16) and atom economy (97%) show that the present protocol is sustainable and economical. Also, the reactions were carried out in water under environmentally benign conditions that avoids use of any additives or hazardous solvents.