bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monodispersed Bioactive Glass Submicron Particles and Their Effect on Bone Marrow and Adipose Tissue‐Derived Stem Cells
Authors: Tsigkou Olga , Labbaf Sheyda , Stevens Molly M. , Porter Alexandra E. , Jones Julian R. 
Published: July 2013

AbstractSpherical monodispersed bioactive particles are potential candidates for nanocomposite synthesis or as injectable particles that could be internalized by cells for the local sustained delivery of inorganic therapeutic ions (e.g., calcium or strontium). Particles are also likely to be released from porous bioactive glass and sol–gel hybrid scaffolds as they degrade; thus, it is vital to investigate their interaction with cells. Spherical monodispersed bioactive glass particles (mono‐SMBG), with diameters of 215 ± 20 nm are synthesized using a modified Stöber process. Confocal and transmission electron microscopy demonstrate that mono‐SMBGs are internalized by human bone marrow (MSCs) and adipose‐derived stem cells (ADSCs) and located within cell vesicles and in the cytoplasm. Particle dissolution inside the cells is observed. Alamar Blue, MTT and Cyquant assays demonstrate that 50 μg mL−1 of mono‐SMBGs did not inhibit significantly MSC or ADSC metabolic activity. However, at higher concentrations (100 and 200 μg mL−1) small decrease in metabolic activity and total DNA is observed. Mono‐SMBG did not induce ALPase activity, an early marker of osteogenic differentiation, without osteogenic supplements; however, in their presence osteogenic differentiation is achieved. Additionally, large numbers of particles are internalized by the cells but have little effect on cell behavior.
Quantification of Whole Body and Excreted Carbon Nanohorns Intravenously Injected into Mice
Authors: Zhang Minfang , Tahara Yoshio , Yang Mei , Zhou Xin , Iijima Sumio , Yudasaka Masako 
Published: July 2013

AbstractWith the increase in the projected use of nanocarbons, such as carbon nanohorns (CNHs), carbon nanotubes (CNTs), and nanographenes, in medicine, the biodegradation and excretion of these materials has attracted increasing interest. Here, the excretion and pharmacokinetics of Gd2O3 nanoparticle labels encapsulated within CNHs after their intravenous injection into mice is studied. The results show that CNHs quantitatively changed with the postinjection time in blood vessels, livers, and other organs. About 40% of the injected CNHs are lost from the mouse body at a postinjection time of 30 d; 15% are excreted in feces, most likely via the bililary pathway into the intestine, whereas the remaining 25% are inferred to be partly or completely degraded.
Influence of Silicon Nanoscale Building Blocks Size and Carbon Coating on the Performance of Micro‐Sized Si–C Composite Li‐Ion Anodes
Authors: Yi Ran , Dai Fang , Gordin Mikhail L. , Sohn Hiesang , Wang Donghai 
Published: July 2013

AbstractSilicon has been intensively pursued as the most promising anode material for Li‐ion batteries due to its high theoretical capacity of 3579 mAh/g. Micro‐sized Si–C composites composed of nanoscale primary building blocks are attractive Si‐based anodes for practical application because they not only achieve excellent cycling stability, but also offer both gravimetric and volumetric capacity. However, the effects of key parameters in designing such materials on their electrochemical performance are unknown and how to optimize them thus remains to be explored. Herein, the influence of Si nanoscale building block size and carbon coating on the electrochemical performance of the micro‐sized Si–C composites is investigated. It is found that the critical Si building block size is 15 nm, which enables a high capacity without compromising the cycling stability, and that carbon coating at higher temperature improves the first cycle coulombic efficiency (CE) and the rate capability. Corresponding reasons underlying electrochemical performance are revealed by various characterizations. Combining both optimized Si building block size and carbon coating temperature, the resultant composite can sustain 600 cycles at 1.2 A/g with a fixed lithiation capacity of 1200 mAh/g, the best cycling performance with such a high capacity for micro‐sized Si‐based anodes.
No association between simian virus 40 and diffuse malignant mesothelioma of the pleura in Iranian patients: A molecular and epidemiologic case–control study of 60 patients
Authors: Mohammad‐Taheri Zohreh , Nadji Seyed Alireza , Raisi Farshid , Mohammadi Forouzan , Bahadori Moslem , Mark Eugene Jerome 
Published: July 2013

AbstractBackgroundDiffuse malignant mesothelioma (DMM) is increasing in incidence on a worldwide basis and is linked to exposure to asbestos. Simian virus 40 (SV40), a DNA virus, was introduced inadvertently to human populations through contaminated polio vaccine during the years 1956–1963. It has been associated with various types of malignancy in animal experiments. There have been suggestions that SV40 might play a role in the pathogenesis of DMM.ObjectiveTo evaluate the association between SV40 and DMM in Iranian patients.MethodIn a case–control study between the years 2007–2008, isolated DNA from 60 paraffin blocks of patients with DMM and 60 controls was assessed to detect three human polyomaviruses (JCV, BKV, and SV40) using three different sets of primers by multiplex nested PCR analysis. We related the patients with diffuse malignant mesotheioma to possible sites of exposure to asbestos.ResultsNone of the DMMs nor any patient in the control group had SV40 genome on polymerase chain reaction (PCR). All of the cases were SV40 T antigen negative.ConclusionThis study suggests that DMM is independent of SV40 infection in Iran. Am. J. Ind. Med. 56:1221–1225, 2013. © 2013 Wiley Periodicals, Inc.
Migratorische Insertion von Alkenen in Metall‐Sauerstoff‐ und Metall‐Stickstoff‐Bindungen
Authors: Hanley Patrick S. , Hartwig John F. 
Published: July 2013

AbstractDie Insertion ungesättigter Liganden in M‐C‐ oder M‐H‐Bindungen verläuft über eine migratorische Insertion, die eine fundamentale metallorganische Reaktion ist. Jüngste Berichte bestätigen migratorische Insertionen von Alkenen in M‐O‐ und M‐N‐Bindungen im Verlauf von Alkenalkoxylierungen bzw. Alkenaminierungen. Wir geben hier einen Überblick über den Stand der Literatur und wollen außerdem betrachten, wie diese jüngsten Studien mit klassischen Experimenten der Bildung von C‐O‐ und C‐N‐Bindungen mit Alkenkomplexen später Übergangsmetalle zusammenhängen.
A Highly Conjugated Benzimidazole Carbene‐Based Ruthenium Sensitizer for Dye‐Sensitized Solar Cells
Authors: Ho Shih‐Yu , Su Chaochin , Li Chung‐Yen , Prabakaran Kumaresan , Shen Ming‐Tai , Chen Ying‐Fan , Chang Wei‐Chun , Tingare Yogesh S. , Akula Suribabu , Tsai Sheng‐Han , Li Wen‐Ren 
Published: July 2013

AbstractA new type of carbene‐based ruthenium sensitizer, CB104, with a highly conjugated ancillary ligand, diphenylvinylthiophene‐substituted benzimidazolepyridine, was designed and developed for dye‐sensitized solar cell applications. The influence of the thiophene antenna on the performance of the cell anchored with CB104 was investigated. Compared with the dye CBTR, the conjugated thiophene in the ancillary ligand of CB104 enhanced the molar extinction coefficient of the intraligand π–π* transition and the intensity of the lower energy metal‐to‐ligand charge‐transfer band. However, the incident photon‐to‐current conversion efficiency spectrum of the cell anchored with CB104 (0.15 mM) showed a maximum of 63 % at 420 nm. The cell sensitized with the dye CB104 attained a power conversion efficiency of 7.30 %, which was lower than that of the cell with nonconjugated sensitizer CBTR (8.92 %) under the same fabrication conditions. The variation in the performance of these two dyes demonstrated that elongating the conjugated light‐harvesting antenna resulted in the reduction of short‐circuit photocurrent density, which might have been due to the aggregation of dye molecules. In the presence of a coabsorbate, chenodeoxycholic acid, the CB104‐sensitized cell exhibited an enhanced photocurrent density and achieved a photovoltaic efficiency of 8.36 %.
Guaranteed Cost Stabilization of Cellular Neural Networks with Time‐Varying Delay
Authors: He Hanlin , Yan Lu , Tu Jianjun 
Published: July 2013

AbstractGuaranteed cost stabilization of cellular neural networks with time‐varying delay (DCNNs) is considered in this paper. Via applying the zoned discussion and maximum synthesis (ZDMS) in DCNNs and Lyapunov–Krasovskii functional, a less conservative feedback control law in the form of quadratic matrix inequality (QMI) is derived to achieve globally asymptotic stability of the system.
Segmental folding of chromosomes: A basis for structural and regulatory chromosomal neighborhoods?
Authors: Nora Elphège P. , Dekker Job , Heard Edith 
Published: July 2013

AbstractWe discuss here a series of testable hypotheses concerning the role of chromosome folding into topologically associating domains (TADs). Several lines of evidence suggest that segmental packaging of chromosomal neighborhoods may underlie features of chromatin that span large domains, such as heterochromatin blocks, association with the nuclear lamina and replication timing. By defining which DNA elements preferentially contact each other, the segmentation of chromosomes into TADs may also underlie many properties of long‐range transcriptional regulation. Several observations suggest that TADs can indeed provide a structural basis to regulatory landscapes, by controlling enhancer sharing and allocation. We also discuss how TADs may shape the evolution of chromosomes, by causing maintenance of synteny over large chromosomal segments. Finally we suggest a series of experiments to challenge these ideas and provide concrete examples illustrating how they could be practically applied.
Comparison of the binding behavior of FCCP with HSA and HTF as determined by spectroscopic and molecular modeling techniques
Authors: Moghaddam Maryam Mahmoodian , Pirouzi Malihe , Saberi Mohammad Reza , Chamani Jamshidkhan 
Published: July 2013

ABSTRACTThe interaction of carbonylcyanide p‐(trifluoromethoxy) phenylhydrazone (FCCP) with human serum albumin (HSA) and human transferrin (HTF) was investigated using multiple spectroscopy, molecular modeling, zeta‐potential and conductometry measurements of aqueous solutions at pH 7.4. The fluorescence, UV/vis and polarization fluorescence spectroscopy data disclosed that the drug–protein complex formation occurred through a remarkable static quenching. Based on the fluorescence quenching, two sets of binding sites with distinct affinities for FCCP existed in the two proteins. Steady‐state and polarization fluorescence analysis showed that there were more affinities between FCCP and HSA than HTF. Far UV‐CD and synchronous fluorescence studies indicated that FCCP induced more structural changes on HSA. The resonance light scattering (RLS) and zeta‐potential measurements suggested that HTF had a greater resistance to drug aggregation, whereas conductometry measurements expressed the presence of free ions improving the resistance of HSA to aggregation. Thermodynamic measurements implied that a combination of electrostatic and hydrophobic forces was involved in the interaction between FCCP with both proteins. The phase diagram plots indicated that the presence of second binding site on HSA and HTF was due to the existence of intermediate structures. Site marker competitive experiments demonstrated that FCCP had two distinct binding sites in HSA which were located in sub‐domains IIA and IIIA and one binding site in the C‐lobe of HTF as confirmed by molecular modeling. The obtained results suggested that both proteins could act as drug carriers, but that the HSA potentially had a higher capacity for delivering FCCP to cancerous tissues. Copyright © 2013 John Wiley & Sons, Ltd.
Sensitive and selective system of benzene detection based on a cataluminescence sensor
Authors: Li Bo , Zhang Yuejin , Liu Juefu , Xie Xin , Zou Dan , Li Minqiang , Liu Jinhuai 
Published: July 2013

ABSTRACTAu/La2O3 nanomaterials were prepared through calcining Au‐modified La(OH)3 precursors. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X‐ray diffractometry (XRD) were employed to characterize the as‐prepared samples. Benzene, a common volatile organic compound, was selected as a model to investigate the cataluminescence (CTL)‐sensing properties of the Au/La2O3 nanomaterials. Results indicated that the as‐prepared Au/La2O3 exhibited outstanding CTL properties such as stable intensity, high signal‐to‐noise values, and short response and recovery times. Under optimized conditions, the benzene assay exhibited a broad linear range of 1–4000 ppm, with a limit of detection of 0.7 ppm, which was below the standard permitted concentrations. Furthermore, the gas sensor system showed outstanding selectivity for benzene compared with seven other types of common volatile organic compounds (VOCs). The proposed gas sensor showed good characteristics with high selectivity, fast response time and long lifetime, which suggested the promising application of the Au/La2O3 nanomaterials as a novel highly efficient CTL‐sensing material. Copyright © 2013 John Wiley & Sons, Ltd.
The effects of experimental conditions of fluorescence quenching on the binding parameters of apigenin to bovine serum albumin by response surface methods
Authors: Tang Lin , Jia Wanteng , Zhang Dong 
Published: July 2013

ABSTRACTA fluorescence quenching technique is often used to study interactions between small molecules and serum albumin. However, the results are quite different by using spectroscopic techniques on the same drug‐protein interaction research and they may be affected by different conditions (e.g. working solution of pH and ionic strength). In this research, using apigenin as an example, the effect of experimental conditions of fluorescence quenching on the binding parameters of drug to bovine serum albumin was investigated using a response surface method (RSM). The effect of pH, the concentration of NaCl and the concentration Mg2+ on the quenching constant (KSV), the apparent association constant (Ka) and the number of binding sites (n) was studied by single‐factor experiments with pH, [NaCl] and [Mg2+] as independent variables and KSV, Ka and n as response values. Prediction models were fit to a quadratic polynomial regression equation and the results showed that both KSV and n displayed a second‐order model, whereas Ka displayed linear relation dependence on pH, [NaCl] and [Mg2+]. Under these experimental conditions, [NaCl] was the most significant (p < 0.05) impact factor on KSV and Ka, whereas n was most affected by pH (p < 0.05). Copyright © 2013 John Wiley & Sons, Ltd.
Development of a highly sensitive chemiluminescent assay for hydrogen peroxide under neutral conditions using acridinium ester and its application to an enzyme immunoassay
Authors: Arakawa Hidetoshi , Tsuruoka Keiko , Ohno Ken‐ichi , Tajima Noriko , Nagano Hiromi 
Published: July 2013

ABSTRACTWe developed a highly sensitive chemiluminescent (CL) assay for hydrogen peroxide using 10‐methyl‐9‐(phenoxycarbonyl) acridinium fluorosulfonate (PMAC) that produced chemiluminescence under neutral conditions and applied it to an enzyme immunoassay (EIA). One picomole of hydrogen peroxide could be detected using the optimized PMAC‐CL method and 6.2 × 10‐20 mol β‐d‐galactosidase (β‐gal) could be detected by combining an indoxyl derivative substrate and the proposed PMAC‐CL method. This highly sensitive CL β‐gal assay was applied to an EIA for thyroid‐stimulating hormone (TSH) using β‐gal as a label enzyme; 0.02–100.0 μU/mL TSH in human serum could be assayed directly and with high reproducibility. Copyright © 2013 John Wiley & Sons, Ltd.
Structural and luminescence properties of Y2‐xGeMoO8:REx (RE = Eu, Tb) phosphors
Authors: Li Naixu , Zhou Jiancheng , Sun Yueming 
Published: July 2013

ABSTRACTY2‐xGeMoO8:REx (RE = Eu, Tb) phosphors were synthesized using a facile sol–gel method. The morphology and structure of the phosphors were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X‐ray diffraction (XRD); while their luminescent properties were investigated by photoluminescence (PL) spectrometry. Our results reveal that all of these Y2‐xGeMoO8:REx (RE = Eu, Tb) phosphors adopted the tetragonal phase, belonging to Scheelite (CaWO4) structure. The obtained YGeMoO8:Eu phosphors exhibit a strong emission in the red light range which can be assigned to the 5D0 → 7F2 transition of Eu3+ when it is excited at 459 nm. Under 392 and 489 nm excitation, the YGeMoO8:Tb phosphors present predominant green emission (5D4 → 7F5) at 540 nm. The highest emission of the phosphors can be achieved by adjusting the doping concentration to be 0.25 for Eu3+ and 0.15 for Tb3+, respectively. The promising luminescence properties of these materials indicate that they can be potentially applied to white‐light‐emitting diodes. Copyright © 2013 John Wiley & Sons, Ltd.
Kinetic isotope effects significantly influence intracellular metabolite 13C labeling patterns and flux determination
Authors: Wasylenko Thomas M. , Stephanopoulos Gregory 
Published: July 2013

AbstractRigorous mathematical modeling of carbon‐labeling experiments allows estimation of fluxes through the pathways of central carbon metabolism, yielding powerful information for basic scientific studies as well as for a wide range of applications. However, the mathematical models that have been developed for flux determination from 13C labeling data have commonly neglected the influence of kinetic isotope effects on the distribution of 13C label in intracellular metabolites, as these effects have often been assumed to be inconsequential. We have used measurements of the 13C isotope effects on the pyruvate dehydrogenase enzyme from the literature to model isotopic fractionation at the pyruvate node and quantify the modeling errors expected to result from the assumption that isotope effects are negligible. We show that under some conditions kinetic isotope effects have a significant impact on the 13C labeling patterns of intracellular metabolites, and the errors associated with neglecting isotope effects in 13C‐metabolic flux analysis models can be comparable in size to measurement errors associated with GC–MS. Thus, kinetic isotope effects must be considered in any rigorous assessment of errors in 13C labeling data, goodness‐of‐fit between model and data, confidence intervals of estimated metabolic fluxes, and statistical significance of differences between estimated metabolic flux distributions.
The Conformation of a Ribose Derivative in Aqueous Solution: A Neutron‐Scattering and Molecular Dynamics Study
Authors: Mason Philip E. , Neilson George W. , Saboungi Marie‐Louise , Brady John W. 
Published: July 2013

ABSTRACTThe structure of aqueous solutions of methyl β‐d‐ribofuranoside was investigated by coupling molecular dynamics (MD) simulations and neutron scattering measurements with isotopic substitution. Using a sample of the sugar isotopically‐labeled at a single unique position, neutron scattering structure factors and radial distribution functions can be compared with MD simulations constrained to different conformations to determine which conformer best fits the experimental results. Three different simulations were performed with the methyl ether group of the sugar unconstrained and constrained in each of its staggered orientations. The results of the unconstrained simulation showed that the methyl ester group occupied predominantly the 300° position, which is in agreement with the diffraction experimental results. This result suggests that the molecular mechanics force field used in the simulation adequately describes the conformation of the 1‐methyl ether group in the methyl β‐d‐ribofuranoside. © 2013 Wiley Periodicals, Inc. Biopolymers 99: 739–745, 2013.
Strategies for profiling native S‐nitrosylation
Authors: Majmudar Jaimeen D. , Martin Brent R. 
Published: July 2013

ABSTRACTCysteine is a uniquely reactive amino acid, capable of undergoing both nucleophlilic and oxidative post‐translational modifications. One such oxidation reaction involves the covalent modification of cysteine via the gaseous second messenger nitric oxide (NO), termed S‐nitrosylation (SNO). This dynamic post‐translational modification is involved in the redox regulation of proteins across all phylogenic kingdoms. In mammals, calcium‐dependent activation of NO synthase triggers the local release of NO, which activates nearby guanylyl cyclases and cGMP‐dependent pathways. In parallel, diffusible NO can locally modify redox active cellular thiols, functionally modulating many redox sensitive enzymes. Aberrant SNO is implicated in the pathology of many diseases, including neurodegeneration, inflammation, and stroke. In this review, we discuss current methods to label sites of SNO for biochemical analysis. The most popular method involves a series of biochemical steps to mask free thiols followed by selective nitrosothiol reduction and capture. Other emerging methods include mechanism‐based phosphine probes and mercury enrichment chemistry. By bridging new enrichment approaches with high‐resolution mass spectrometry, large‐scale analysis of protein nitrosylation has highlighted new pathways of oxidative regulation. © 2013 Wiley Periodicals, Inc. Biopolymers 101: 173–179, 2014.
Structural biology computing: Lessons for the biomedical research sciences
Authors: Morin Andrew , Sliz Piotr 
Published: July 2013

ABSTRACTThe field of structural biology, whose aim is to elucidate the molecular and atomic structures of biological macromolecules, has long been at the forefront of biomedical sciences in adopting and developing computational research methods. Operating at the intersection between biophysics, biochemistry, and molecular biology, structural biology's growth into a foundational framework on which many concepts and findings of molecular biology are interpreted1 has depended largely on parallel advancements in computational tools and techniques. Without these computing advances, modern structural biology would likely have remained an exclusive pursuit practiced by few, and not become the widely practiced, foundational field it is today. As other areas of biomedical research increasingly embrace research computing techniques, the successes, failures and lessons of structural biology computing can serve as a useful guide to progress in other biomedically related research fields. © 2013 Wiley Periodicals, Inc. Biopolymers 99: 809–816, 2013.