bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metal Transition in Sodium–Ammonia Nanodroplets
Authors: Hartweg Sebastian , West Adam H. C. , Yoder Bruce L. , Signorell Ruth 
Published: August 2016

AbstractThe famous nonmetal‐to‐metal transition in Na–ammonia solutions is investigated in nanoscale solution droplets by photoelectron spectroscopy. In agreement with the bulk solutions, a strong indication for a transition to the metallic state is found at an average metal concentration of 8.8±2.2 mole%. The smallest entity for the phase transition to be observed consists of approximately 100–200 solvent molecules. The quantification of this critical entity size is a stepping stone toward a deeper understanding of these quantum–classical solutions through direct modeling at the molecular level.
Application of a Palladium‐Catalyzed C−H Functionalization/Indolization Method to Syntheses of cis‐Trikentrin A and Herbindole B
Authors: Leal Raul A. , Bischof Caroline , Lee Youjin V. , Sawano Shota , McAtee Christopher C. , Latimer Luke N. , Russ Zachary N. , Dueber John E. , Yu Jin‐Quan , Sarpong Richmond 
Published: August 2016

AbstractWe describe herein formal syntheses of the indole alkaloids cis‐trikentrin A and herbindole B from a common meso‐hydroquinone intermediate prepared by a ruthenium‐catalyzed [2+2+1+1] cycloaddition that has not been used previously in natural product synthesis. Key steps include a sterically demanding Buchwald–Hartwig amination as well as a unique C(sp3)−H amination/indole formation. Studies toward a selective desymmetrization of the meso‐hydroquinone are also reported.
Discerning the Chemistry in Individual Organelles with Small‐Molecule Fluorescent Probes
Authors: Xu Wang , Zeng Zebing , Jiang Jian‐Hui , Chang Young‐Tae , Yuan Lin 
Published: August 2016

AbstractPrinciple has it that even the most advanced super‐resolution microscope would be futile in providing biological insight into subcellular matrices without well‐designed fluorescent tags/probes. Developments in biology have increasingly been boosted by advances of chemistry, with one prominent example being small‐molecule fluorescent probes that not only allow cellular‐level imaging, but also subcellular imaging. A majority, if not all, of the chemical/biological events take place inside cellular organelles, and researchers have been shifting their attention towards these substructures with the help of fluorescence techniques. This Review summarizes the existing fluorescent probes that target chemical/biological events within a single organelle. More importantly, organelle‐anchoring strategies are described and emphasized to inspire the design of new generations of fluorescent probes, before concluding with future prospects on the possible further development of chemical biology.
Cyclometalated Palladium(II) N‐Heterocyclic Carbene Complexes: Anticancer Agents for Potent In Vitro Cytotoxicity and In Vivo Tumor Growth Suppression
Authors: Fong Tommy Tsz‐Him , Lok Chun‐Nam , Chung Clive Yik‐Sham , Fung Yi‐Man Eva , Chow Pui‐Keong , Wan Pui‐Ki , Che Chi‐Ming 
Published: August 2016

AbstractPalladium(II) complexes are generally reactive toward substitution/reduction, and their biological applications are seldom explored. A new series of palladium(II) N‐heterocyclic carbene (NHC) complexes that are stable in the presence of biological thiols are reported. A representative complex, [Pd(C^N^N)(N,N′‐nBu2NHC)](CF3SO3) (Pd1 d, HC^N^N=6‐phenyl‐2,2′‐bipyridine, N,N′‐nBu2NHC=N,N′‐di‐n‐butylimidazolylidene), displays potent killing activity toward cancer cell lines (IC50=0.09–0.5 μm) but is less cytotoxic toward a normal human fibroblast cell line (CCD‐19Lu, IC50=11.8 μm). In vivo anticancer studies revealed that Pd1 d significantly inhibited tumor growth in a nude mice model. Proteomics data and in vitro biochemical assays reveal that Pd1 d exerts anticancer effects, including inhibition of an epidermal growth factor receptor pathway, induction of mitochondrial dysfunction, and antiangiogenic activity to endothelial cells.
Effect of block composition on the morphology, hydration, and transport properties of sulfonated PS‐b‐PEGPEM‐b‐PS
Authors: Pérez‐Pérez Maritza , Suleiman David 
Published: August 2016

ABSTRACTThis work discusses the effect of block composition on the properties of proton conducting polymer membranes. A homopolymer and two block copolymers were synthesized using atom transfer radical polymerization. The homopolymer poly(ethylene glycol phenyl ether methacrylate) (PEGPEM) was used as a bifunctional macroinitiator. Polystyrene (PS), was added to both sides of PEGPEM (A) with two different percentages of PS (B) (i.e., 18 and 31%). These copolymers, BAB 18, BAB 31 and the homopolymer A, were completely sulfonated (SA, SBAB 18 and SBAB 31). The resulting polymers produced different water absorption values and transport properties for direct methanol fuel cell (DMFC) applications. The nanostructure and morphology of the casted membranes were studied using small‐angle X‐ray scattering and atomic force microscopy. The results revealed that all six membranes exhibited a disordered phase‐segregated morphology, which changed on sulfonation into small‐interconnected ionic domains. Normalized DMFC selectivities (proton conductivity over methanol permeability divided by the respective values for Nafion®) were calculated and ranged from 1.16 (SBAB 31) to 15.30 (BAB 18), indicating that the performance of these materials can be comparable or better than Nafion®. Transport property results also suggest that chemistry (block nature and composition), morphology and water content play a critical role in the transport mechanism of protons and methanol. For example, the percentage of B in BAB 18 provides shorter interstitial ionic distances and sufficient water content to produce high proton conductivity, while maintaining low methanol permeability in a multi‐ionic proton exchange membrane. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44343.
Discriminating typical and atypical cystic fibrosis‐related bacteria by multiplex PNA‐FISH
Authors: Lopes Susana P. , Carvalho Daniel T. , Pereira Maria O. , Azevedo Nuno F. 
Published: August 2016

ABSTRACTThis study aims to report the development of peptide nucleic acid (PNA) probes to specifically detect the cystic fibrosis (CF)‐associated traditional and atypical species Pseudomonas aeruginosa and Inquilinus limosus, respectively. PNA probes were designed in silico, developed and tested in smears prepared in phosphate‐buffer saline (PBS), and in artificial sputum medium (ASM). A multiplex fluorescent in situ hybridization (FISH) approach using the designed probes was further validated in artificially contaminated clinical sputum samples and also applied in polymicrobial 24 h‐old biofilms involving P. aeruginosa, I. limosus, and other CF‐related bacteria. Both probes showed high predictive and experimental specificities and sensitivities. The multiplex PNA‐FISH assay, associated with non‐specific staining, was successfully adapted in the clinical samples and in biofilms of CF‐related bacteria, allowing differentiating the community members and inferring about microbial‐microbial interactions within the consortia. This study revealed the great potential of PNA‐FISH as a diagnostic tool to discriminate between classical and less common CF‐associated bacteria, being suitable to further describe species‐dependent prevention strategies and deliver more effective target control therapeutics. Biotechnol. Bioeng. 2017;114: 355–367. © 2016 Wiley Periodicals, Inc.
A pumpless multi‐organ‐on‐a‐chip (MOC) combined with a pharmacokinetic–pharmacodynamic (PK–PD) model
Authors: Lee Hyuna , Kim Dae Shik , Ha Sang Keun , Choi Inwook , Lee Jong Min , Sung Jong Hwan 
Published: August 2016

ABSTRACTA multi‐organ‐on‐a‐chip (MOC), also known as a human‐on‐a‐chip, aims to simulate whole body response to drugs by connecting microscale cell cultures of multiple tissue types via fluidic channels and reproducing the interaction between them. While several studies have demonstrated the usefulness of MOC at a proof‐of‐concept level, improvements are needed to enable wider acceptance of such systems; ease of use for general biological researchers, and a mathematical framework to design and interpret the MOC systems. Here, we introduce a pumpless, user‐friendly MOC which can be easily assembled and operated, and demonstrate the use of a PK–PD model for interpreting drug's action inside the MOC. The metabolism‐dependent anticancer activity of a flavonoid, luteolin, was evaluated in a two‐compartment MOC containing the liver (HepG2) and the tumor (HeLa) cells, and the observed anticancer activity was significantly weaker than that anticipated from a well plate study. Simulation of a PK–PD model revealed that simultaneous metabolism and tumor‐killing actions likely resulted in a decreased anti‐cancer effect. Our work demonstrates that the combined platform of mathematical PK–PD model and an experimental MOC can be a useful tool for gaining an insight into the mechanism of action of drugs with interactions between multiple organs. Biotechnol. Bioeng. 2017;114: 432–443. © 2016 Wiley Periodicals, Inc.
The role of host cell physiology in the productivity of the baculovirus‐insect cell system: Fluxome analysis of Trichoplusia ni and Spodoptera frugiperda cell lines
Authors: Monteiro Francisca , Bernal Vicente , Alves Paula M. 
Published: August 2016

ABSTRACTThe Insect Cell‐Baculovirus Expression Vector System (IC‐BEVS) is broadly used for the production of recombinant proteins and vaccine manufacture, yet the host physiological aspects that contribute to productivity are to be disclosed. This work provides the first quantitative analysis of the metabolic fluxes of High Five cells. This analysis was conducted in comparison with Sf9 cells, another major host for biologicals production via BEVS. Moreover, herein is presented, for the first time, quantitative data of the relative contribution of sugars and amino acids catabolism to the activity of the TCA cycle in Sf9 and High Five cells. High Five cells metabolic activity was markedly influenced by the amino acids concentration in culture medium, which determine the rates of amino acid catabolism, carbon overflow and by‐product formation. This characteristic of High Five cells was reflected in the activities of anaplerotic metabolism and the TCA cycle, which may not work as a true cycle as a function of medium composition. This was not the case for Sf9 cells, in which the glucose carbon incorporation in the TCA cycle was significantly higher and lactate production minor. Following infection, the decrease in by‐product accumulation rates was accompanied by an increase in net ATP synthesis in Sf9 and High Five cells, although through distinct mechanisms cell‐line dependent. The impact of baculovirus infection on cellular metabolic status highlights the capacity of this virus to re‐direct the cellular fluxome toward ATP production to support replication and progeny generation. These results pave the way to deepen our knowledge on the relationship between a host cell and the virus, contributing to disclosing the metabolic determinants that contribute to productivity. Biotechnol. Bioeng. 2017;114: 674–684. © 2016 Wiley Periodicals, Inc.
The future of protein scaffolds as affinity reagents for purification
Authors: Dias Ana M.G.C. , Roque Ana C.A. 
Published: August 2016

ABSTRACTAffinity purification is one of the most powerful separation techniques extensively employed both at laboratory and production scales. While antibodies still represent the gold standard affinity reagents, others derived from non‐immunoglobulin scaffolds emerged as interesting alternatives in particular for affinity purification. The lower costs of production, fast ligand development, and high robustness are appealing advantages of non‐immunoglobulin scaffolds. These have successfully been used in the affinity purification of relevant targets as antibodies, human serum albumin, transferrin, and other biomarkers, as reviewed in this work. Furthermore, a critical assessment on the strengths, weaknesses, opportunities, and threats related with the implementation of non‐immunoglobulin scaffolds as ligands in affinity purification are discussed. Biotechnol. Bioeng. 2017;114: 481–491. © 2016 Wiley Periodicals, Inc.
A UPLC–MS/MS approach for simultaneous determination of eight flavonoids in rat plasma, and its application to pharmacokinetic studies of Fu‐Zhu‐Jiang‐Tang tablet in rats
Authors: Tao Yi , Chen Xi , Jiang Yanhui , Cai Baochang 
Published: August 2016

AbstractThe purpose of this study is to establish and validate a UPLC–MS/MS approach to determine eight flavonoids in biological samples and apply the method to pharmacokinetic study of Fu‐Zhu‐Jiang‐Tang tablet. A Waters BEH C18 UPLC column was employed with methanol/0.1% formic acid–water as mobile phases. The mass analysis was carried out in a triple quadrupole mass spectrometer using multiple reaction monitoring with negative scan mode. A one‐step protein precipitation by methanol was used to extract the analytes from blood. Eight major flavonoids were selected as markers. Our results showed that calibration curves for 3′‐hydroxypuerarin, mirificin, puerarin, 3′‐methoxypuerarin, daidzin, rutin, astragalin and daidzein displayed good linear regression (r2 > 0.9986). The intra‐day and inter‐day precisions (RSD) of the eight flavonoids at high, medium and low levels were <8.03% and the bias of the accuracies ranged from −5.20 to 6.75%.The extraction recoveries of the eight flavonoids were from 91.4 to 100.5% and the matrix effects ranged from 89.8 to 103.8%. The validated approach was successfully applied to a pharmacokinetic study in Sprague–Dawley rats after oral administration of FZJT tablet. Double peaks were emerged in curves of mean plasma concentration for 3′‐methoxypuerarin, which was reported for the first time.
Hemodynamics‐driven deposition of intraluminal thrombus in abdominal aortic aneurysms
Authors: Di Achille P. , Tellides G. , Humphrey J. D. 
Published: August 2016

AbstractAccumulating evidence suggests that intraluminal thrombus plays many roles in the natural history of abdominal aortic aneurysms. There is, therefore, a pressing need for computational models that can describe and predict the initiation and progression of thrombus in aneurysms. In this paper, we introduce a phenomenological metric for thrombus deposition potential and use hemodynamic simulations based on medical images from 6 patients to identify best‐fit values of the 2 key model parameters. We then introduce a shape optimization method to predict the associated radial growth of the thrombus into the lumen based on the expectation that thrombus initiation will create a thrombogenic surface, which in turn will promote growth until increasing hemodynamically induced frictional forces prevent any further cell or protein deposition. Comparisons between predicted and actual intraluminal thrombus in the 6 patient‐specific aneurysms suggest that this phenomenological description provides a good first estimate of thrombus deposition. We submit further that, because the biologically active region of the thrombus appears to be confined to a thin luminal layer, predictions of morphology alone may be sufficient to inform fluid‐solid–growth models of aneurysmal growth and remodeling.
Consumption of a high‐fat meal was associated with an increase in monocyte adhesion molecules, scavenger receptors, and Propensity to Form Foam Cells
Authors: Henning A. L. , Venable A. S. , Vingren J. L. , Hill D. W. , McFarlin B. K. 
Published: August 2016

BackgroundMacrophage‐derived foam cells are the predominant component of arterial plaques in the early stages of atherosclerosis. One factor that poses a major risk for plaque development is high levels of plasma low‐density lipoprotein (LDL) as a result of a high‐fat meal. In order to better understand how an individuals' diet affects arterial plaque deposition via the process of foam cell formation, we measured the acute circulating monocyte activity response after consuming a high‐fat meal (85% of daily fat allowance).Materials and MethodsVenous blood samples from 17 participants were acquired on a FlowSight. Samples were analyzed to identify nonclassical (CD14+/16+) and classical (CD14+/16−) monocytes. We measured monocyte concentration, adhesion molecule expression, CD36 expression, and oxidized LDL (oxLDL) endocytosis for preprandial 1, 3, and 5 h postprandial.ResultsConsuming a high‐fat meal caused increases in oxLDL uptake, adhesion molecule expression, and CD36 expression in both classical and nonclassical monocytes, with the nonclassical monocytes responding with larger increases than the classical monocytes.ConclusionThese results suggest that consumption of a high‐fat meal increased the potential of monocytes to become foam cells, and implicates nonclassical monocytes as having greater potential than classical monocytes to become foam cells. © 2016 International Clinical Cytometry Society
Neuroprotective effects of testosterone metabolites and dependency on receptor action on the morphology of somatic motoneurons following the death of neighboring motoneurons
Authors: Cai Yi , Chew Cory , Muñoz Fernando , Sengelaub Dale R. 
Published: August 2016

ABSTRACTPartial depletion of spinal motoneuron populations induces dendritic atrophy in neighboring motoneurons, and treatment with testosterone is neuroprotective, attenuating induced dendritic atrophy. In this study we examined whether the protective effects of testosterone could be mediated via its androgenic or estrogenic metabolites. Furthermore, to assess whether these neuroprotective effects were mediated through steroid hormone receptors, we used receptor antagonists to attempt to prevent the neuroprotective effects of hormones after partial motoneuron depletion. Motoneurons innervating the vastus medialis muscles of adult male rats were selectively killed by intramuscular injection of cholera toxin‐conjugated saporin. Simultaneously, some saporin‐injected rats were treated with either dihydrotestosterone or estradiol, alone or in combination with their respective receptor antagonists, or left untreated. Four weeks later, motoneurons innervating the ipsilateral vastus lateralis muscle were labeled with cholera toxin‐conjugated horseradish peroxidase, and dendritic arbors were reconstructed in three dimensions. Compared with intact normal animals, partial motoneuron depletion resulted in decreased dendritic length in remaining quadriceps motoneurons. Dendritic atrophy was attenuated with both dihydrotestosterone and estradiol treatment to a degree similar to that seen with testosterone, and attenuation of atrophy was prevented by receptor blockade. Together, these findings suggest that neuroprotective effects on motoneurons can be mediated by either androgenic or estrogenic hormones and require action via steroid hormone receptors, further supporting a role for hormones as neurotherapeutic agents in the injured nervous system. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 691–707, 2017
Alterations in brain white matter contributing to age‐related slowing of task switching performance: The role of radial diffusivity and magnetization transfer ratio
Authors: Serbruyns Leen , Leunissen Inge , van Ruitenbeek Peter , Pauwels Lisa , Caeyenberghs Karen , Solesio‐Jofre Elena , Geurts Monique , Cuypers Koen , Meesen Raf L. , Sunaert Stefan , Leemans Alexander , Swinnen Stephan P. 
Published: August 2016

Abstract:Successfully switching between tasks is critical in many daily activities. Age‐related slowing of this switching behavior has been documented extensively, but the underlying neural mechanisms remain unclear. Here, we investigated the contribution of brain white matter changes associated with myelin alterations to age‐related slowing of switching performance. Diffusion tensor imaging derived radial diffusivity (RD) and magnetization transfer imaging derived magnetization transfer ratio (MTR) were selected as myelin sensitive measures. These metrics were studied in relation to mixing cost (i.e., the increase in reaction time during task blocks that require task switching) on a local‐global switching task in young (n = 24) and older (n = 22) adults. Results showed that higher age was associated with widespread increases in RD and decreases in MTR, indicative of white matter deterioration, possibly due to demyelination. Older adults also showed a higher mixing cost, implying slowing of switching performance. Finally, mediation analyses demonstrated that decreases in MTR of the bilateral superior corona radiata contributed to the observed slowing of switching performance with increasing age. These findings provide evidence for a role of cortico‐subcortical white matter changes in task switching performance deterioration with healthy aging. Hum Brain Mapp 37:4084–4098, 2016. © 2016 Wiley Periodicals, Inc.
Auditory and visual connectivity gradients in frontoparietal cortex
Authors: Braga Rodrigo M. , Hellyer Peter J. , Wise Richard J. S. , Leech Robert 
Published: August 2016

AbstractA frontoparietal network of brain regions is often implicated in both auditory and visual information processing. Although it is possible that the same set of multimodal regions subserves both modalities, there is increasing evidence that there is a differentiation of sensory function within frontoparietal cortex. Magnetic resonance imaging (MRI) in humans was used to investigate whether different frontoparietal regions showed intrinsic biases in connectivity with visual or auditory modalities. Structural connectivity was assessed with diffusion tractography and functional connectivity was tested using functional MRI. A dorsal–ventral gradient of function was observed, where connectivity with visual cortex dominates dorsal frontal and parietal connections, while connectivity with auditory cortex dominates ventral frontal and parietal regions. A gradient was also observed along the posterior–anterior axis, although in opposite directions in prefrontal and parietal cortices. The results suggest that the location of neural activity within frontoparietal cortex may be influenced by these intrinsic biases toward visual and auditory processing. Thus, the location of activity in frontoparietal cortex may be influenced as much by stimulus modality as the cognitive demands of a task. It was concluded that stimulus modality was spatially encoded throughout frontal and parietal cortices, and was speculated that such an arrangement allows for top–down modulation of modality‐specific information to occur within higher‐order cortex. This could provide a potentially faster and more efficient pathway by which top–down selection between sensory modalities could occur, by constraining modulations to within frontal and parietal regions, rather than long‐range connections to sensory cortices. Hum Brain Mapp 38:255–270, 2017. © 2016 Wiley Periodicals, Inc.