bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cholinergic innervation of principal neurons in the cochlear nucleus of the Mongolian gerbil
Authors: Gillet Charlène , Goyer David , Kurth Stefanie , Griebel Hannah , Kuenzel Thomas 
Published: March 2018

AbstractPrincipal neurons in the ventral cochlear nucleus (VCN) receive powerful ascending excitation and pass on the auditory information with exquisite temporal fidelity. Despite being dominated by ascending inputs, the VCN also receives descending cholinergic connections from olivocochlear neurons and from higher regions in the pontomesencephalic tegmentum. In Mongolian gerbils, acetylcholine acts as an excitatory and modulatory neurotransmitter on VCN neurons, but the anatomical structure of cholinergic innervation of gerbil VCN is not well described. We applied fluorescent immunohistochemical staining to elucidate the development and the cellular localization of presynaptic and postsynaptic components of the cholinergic system in the VCN of the Mongolian gerbil. We found that cholinergic fibers (stained with antibodies against the vesicular acetylcholine transporter) were present before hearing onset at P5, but innervation density increased in animals after P10. Early in development cholinergic fibers invaded the VCN from the medial side, spread along the perimeter and finally innervated all parts of the nucleus only after the onset of hearing. Cholinergic fibers ran in a rostro‐caudal direction within the nucleus and formed en‐passant swellings in the neuropil between principal neurons. Nicotinic and muscarinic receptors were expressed differentially in the VCN, with nicotinic receptors being mostly expressed in dendritic areas while muscarinic receptors were located predominantly in somatic membranes. These anatomical data support physiological indications that cholinergic innervation plays a role in modulating information processing in the cochlear nucleus.
Time course of cytochrome oxidase blob plasticity in the primary visual cortex of adult monkeys after retinal laser lesions
Authors: Farias Mariana F. , Ungerleider Leslie G. , Pereira Sandra S. , Amorim Ana Karla J. , Soares Juliana G. M. , Gattass Ricardo 
Published: March 2018

AbstractWe studied the time course of changes of cytochrome oxidase (CytOx) blob spatial density and blob cross‐sectional area of deprived (D) and nondeprived (ND) portions of V1 in four capuchin monkeys after massive and restricted retinal laser lesions. Laser shots at the border of the optic disc produced massive retinal lesions, while low power laser shots in the retina produced restricted retinal lesions. These massive and restricted retinal lesions were intended to simulate glaucoma and diabetic retinopathy, respectively. We used a Neodymium‐YAG dual frequency laser to make the lesions. We measured Layer III blobs in CytOx‐reacted tangential sections of flat‐mounted preparations of V1. The plasticity of the blob system and that of the ocular dominance columns (ODC) varied with the degree of retinal lesions. We found that changes in the blob system were different from that of the ODC. Blob sizes changed drastically in the region corresponding to the retinal lesion. Blobs were larger and subjectively darker above and below the non deprived ODC than in the deprived columns. With restricted lesions, blobs corresponding to the ND columns had sizes similar to those from non‐lesioned areas. In contrast, blobs corresponding to the deprived columns were smaller than those from nonlesioned areas. With massive lesions, ND blobs were larger than the deprived blobs. Plastic changes in blobs described here occur much earlier than previously described.
Morphological evidence for novel enteric neuronal circuitry in guinea pig distal colon
Authors: Smolilo D.J. , Costa M. , Hibberd T.J. , Wattchow D.A. , Spencer Nick J. 
Published: March 2018

AbstractThe gastrointestinal (GI) tract is unique compared to all other internal organs; it is the only organ with its own nervous system and its own population of intrinsic sensory neurons, known as intrinsic primary afferent neurons (IPANs). How these IPANs form neuronal circuits with other functional classes of neurons in the enteric nervous system (ENS) is incompletely understood. We used a combination of light microscopy, immunohistochemistry and confocal microscopy to examine the topographical distribution of specific classes of neurons in the myenteric plexus of guinea‐pig colon, including putative IPANs, with other classes of enteric neurons. These findings were based on immunoreactivity to the neuronal markers, calbindin, calretinin and nitric oxide synthase. We then correlated the varicose outputs formed by putative IPANs with subclasses of excitatory interneurons and motor neurons. We revealed that calbindin‐immunoreactive varicosities form specialized structures resembling ‘baskets’ within the majority of myenteric ganglia, which were arranged in clusters around calretinin‐immunoreactive neurons. These calbindin baskets directly arose from projections of putative IPANs and represent morphological evidence of preferential input from sensory neurons directly to a select group of calretinin neurons. Our findings uncovered that these neurons are likely to be ascending excitatory interneurons and excitatory motor neurons. Our study reveals for the first time in the colon, a novel enteric neural circuit, whereby calbindin‐immunoreactive putative sensory neurons form specialized varicose structures that likely direct synaptic outputs to excitatory interneurons and motor neurons. This circuit likely forms the basis of polarized neuronal pathways underlying motility.
Numerical zero‐dimensional hepatic artery hemodynamics model for balloon‐occluded transarterial chemoembolization
Authors: Aramburu Jorge , Antón Raúl , Rivas Alejandro , Ramos Juan Carlos , Larraona Gorka S. , Sangro Bruno , Bilbao José Ignacio 
Published: March 2018

AbstractBalloon‐occluded transarterial chemoembolization (B‐TACE) is a valuable treatment option for patients with inoperable malignant tumors in the liver. Balloon‐occluded transarterial chemoembolization consists of the transcatheter infusion of an anticancer drug mixture and embolic agents. Contrary to conventional TACE, B‐TACE is performed via an artery‐occluding microballoon catheter, which makes the blood flow to redistribute due to the intra‐ and extrahepatic arterial collateral circulation. Several recent studies have stressed the importance of the redistribution of blood flow in enhancing the treatment outcome. In the present study, the geometries of a representative hepatic artery and the communicating arcades (CAs) are modeled. An in silico zero‐dimensional hemodynamic model is created by characterizing the geometry and the boundary conditions and then is validated in vitro. The role of CAs is assessed by combining 2 cancer scenarios and 2 catheter locations. The importance of the diameter of the CAs is also studied. Results show that occluding a main artery leads to collateral circulation and CAs start to play a role in blood‐flow redistribution. In summary, numerical zero‐dimensional simulations permit a fast and reliable approach for exploring the blood‐flow redistribution caused by the occlusion of a main artery, and this approach could be used during B‐TACE planning.
Numerical approximation of the electromechanical coupling in the left ventricle with inclusion of the Purkinje network
Authors: Landajuela Mikel , Vergara Christian , Gerbi Antonello , Dedè Luca , Formaggia Luca , Quarteroni Alfio 
Published: March 2018

AbstractIn this work, we consider the numerical approximation of the electromechanical coupling in the left ventricle with inclusion of the Purkinje network. The mathematical model couples the 3D elastodynamics and bidomain equations for the electrophysiology in the myocardium with the 1D monodomain equation in the Purkinje network. For the numerical solution of the coupled problem, we consider a fixed‐point iterative algorithm that enables a partitioned solution of the myocardium and Purkinje network problems. Different levels of myocardium‐Purkinje network splitting are considered and analyzed. The results are compared with those obtained using standard strategies proposed in the literature to trigger the electrical activation. Finally, we present a numerical study that, although performed in an idealized computational domain, features all the physiological issues that characterize a heartbeat simulation, including the initiation of the signal in the Purkinje network and the systolic and diastolic phases.
Plasmonic and Photonic Effects on Hydrogen Evolution over Chemically Modified Titania Inverse Opals
Authors: Rahul Theyyathum Kavil , Sandhyarani Neelakandapillai 
Published: March 2018

AbstractThe photonic effects of chemically modified titania inverse opals can be exploited for improving photocatalytic hydrogen production. This work reports the in situ preparation of gold‐platinum nanoparticle (NP)‐loaded and nitrogen‐fluorine co‐doped titania inverse opal photocatalysts with different photonic band gaps (PBGs). In situ loading of gold and platinum NPs was carried out during the preparation of titania inverse opals by treating the titania precursor with gold chloride and platinum chloride. Au−Pt/N−F TiO2 IO‐460 samples with the photonic effects matching the surface plasmon resonance region of Au NPs displayed a maximum activity with a hydrogen production rate of 134 mmol h−1 g−1. The hydrogen yield (97 mmol h−1 g−1) obtained for Au−Pt/N−F TiO2 IO‐215, with the photonic effects close to the electronic bandgap of titania was also high when compared to that of the nanocrystalline counterpart, Au−Pt/N−F nc‐TiO2 (49 mmol h−1 g−1). Excellent solar hydrogen evolution profile was observed for in situ gold‐platinum NP‐loaded and nitrogen‐fluorine co‐doped titania inverse opal photocatalysts when compared to recent reports.
Spectral Algorithms for Tensor Completion
Authors: Montanari Andrea , Sun Nike 
Published: March 2018

In the tensor completion problem, one seeks to estimate a low‐rank tensor based on a random sample of revealed entries. In terms of the required sample size, earlier work revealed a large gap between estimation with unbounded computational resources (using, for instance, tensor nuclear norm minimization) and polynomial‐time algorithms. Among the latter, the best statistical guarantees have been proved, for third‐order tensors, using the sixth level of the sum‐of‐squares (sos) semidefinite programming hierarchy. However, the sos approach does not scale well to large problem instances. By contrast, spectral methods—based on unfolding or matricizing the tensor—are attractive for their low complexity, but have been believed to require a much larger sample size.This paper presents two main contributions. First, we propose a new method, based on unfolding, which outperforms naive ones for symmetric kth‐order tensors of rank r. For this result we make a study of singular space estimation for partially revealed matrices of large aspect ratio, which may be of independent interest. For third‐order tensors, our algorithm matches the sos method in terms of sample size (requiring about rd3/2 revealed entries), subject to a worse rank condition (r ≪ d3/4 rather than r ≪ d3/2). We complement this result with a different spectral algorithm for third‐order tensors in the overcomplete (r ≥ d) regime. Under a random model, this second approach succeeds in estimating tensors of rank d ≤ r ≪ d3/2 from about rd3/2 revealed entries. © 2018 Wiley Periodicals, Inc.
Effective Dynamics of the Nonlinear Schrödinger Equation on Large Domains
Authors: Buckmaster T. , Germain P. , Hani Z. , Shatah J. 
Published: March 2018

AbstractWe consider the nonlinear Schrödinger (NLS) equation posed on the box [0,L]dwith periodic boundary conditions. The aim is to describe the long‐time dynamics by derivingeffective equationsfor it whenLis large and the characteristic sizeɛof the data is small. Such questions arise naturally when studying dispersive equations that are posed on large domains (like water waves in the ocean), and also in the theory of statistical physics of dispersive waves, which goes by the name of “wave turbulence.” Our main result is deriving a new equation, thecontinuous resonant(CR) equation, which describes the effective dynamics for largeLand smallɛover very large timescales. Such timescales are well beyond the (a) nonlinear timescale of the equation, and (b) the euclidean timescale at which the effective dynamics are given by (NLS) on ℝd. The proof relies heavily on tools from analytic number theory, such as a relatively modern version of the Hardy‐Littlewood circle method, which are modified and extended to be applicable in a PDE setting.© 2018 Wiley Periodicals, Inc.
Strong Photonic‐Band‐Gap Effect on the Spontaneous Emission in 3D Lead Halide Perovskite Photonic Crystals
Authors: Zhou Xue , Li Mingzhu , Wang Kang , Li Huizeng , Li Yanan , Li Chang , Yan Yongli , Zhao Yongsheng , Song Yanlin 
Published: March 2018

AbstractStimulated emission in perovskite‐embedded polymer opal structures is investigated. A polymer opal structure is filled with a perovskite, and perovskite photonic crystals are prepared. The spontaneous emission of the perovskite embedded in the polymer opal structures exhibits clear signatures of amplified spontaneous emission (ASE) via gain modulation. The difference in refractive‐index contrast between the perovskite and the polymer opal is large enough for retaining photonic‐crystals properties. The photonic band gap has a strong effect on the fluorescence emission intensity and lifetime. The stimulated emission spectrum exhibits a narrow ASE rather than a wide fluorescence peak in the thin film.
Molecular Modeling Approach to Determine the Flory‐Huggins Interaction Parameter for Polymer Miscibility Analysis
Authors: Callaway Connor P. , Hendrickson Kayla , Bond Nicholas , Lee Seung Min , Sood Parveen , Jang Seung Soon 
Published: March 2018

AbstractIn this work, we present a thorough procedure for estimating the Flory‐Huggins χ‐parameter for use in atomistic and mesoscale molecular simulations in computational materials science. In particular, we propose improvements upon traditional Flory‐Huggins theory by implementing a Connolly volume normalization (CVN). We apply this technique to several test systems, including a blend of poly (epichlorohydrin) and poly (methyl acrylate), a blend of polyethylene glycol and poly (methyl methacrylate), a blend of polystyrene and deuterated polystyrene, and three molecular‐weight variants (monomer, dimer, and trimer) of a triblock copolymer for use in multicompartment micelle applications. Our results demonstrate that the newly developed procedure offers high accuracy and efficiency in predicting the Flory‐Huggins χ‐parameter for miscibility analysis compared to traditional experimental and computational methods. There are still several factors that cause the magnitude of the χ‐parameter to vary between simulations performed on molecular species with the same identity but different degrees of polymerization; although we discuss possible explanations for these factors, this is nonetheless a primary focus for further exploration into this new methodology.
Revealing the Self‐Degradation Mechanisms in Methylammonium Lead Iodide Perovskites in Dark and Vacuum
Authors: Gunasekaran Rajendra Kumar , Chinnadurai Deviprasath , Selvaraj Aravindha Raja , Rajendiran Rajmohan , Senthil Karuppanan , Prabakar Kandasamy 
Published: March 2018

AbstractOrganic‐inorganic lead halide perovskite phases segregate (and their structures degrade) under illumination, exhibiting a poor stability with hysteresis and producing halide accumulation at the surface.In this work, we observed structural and interfacial dissociation in methylammonium lead iodide (CH3NH3PbI3) perovskites even under dark and vacuum conditions. Here, we investigate the origin and consequences of self‐degradation in CH3NH3PbI3 perovskites stored in the dark under vacuum. Diffraction and photoelectron spectroscopic studies reveal the structural dissociation of perovskites into PbI2, which further dissociates into metallic lead (Pb0) and I2− ions, collectively degrading the perovskite stability. Using TOF‐SIMS analysis, AuI2− formation was directly observed, and it was found that an interplay between CH3NH3+, I3−, and mobile I− ions continuously regenerates more I2− ions, which diffuse to the surface even in the absence of light. Besides, halide diffusion causes a concentration gradient between Pb0 and I2− and creates other ionic traps (PbI2−, PbI−) that segregate as clusters at the perovskite/gold interface. A shift of the onset of the absorption band edge towards shorter wavelengths was also observed by absorption spectroscopy, indicating the formation of defect species upon aging in the dark under vacuum.
Length‐Dependent Manifestation of Vibration Modes Regulates a Specific Intermediate Morphology of Aβ17‐42 in Different Environments
Authors: Choi Hyunsung , Yoon Taeyoung , Na Sungsoo 
Published: March 2018

AbstractVarious cytotoxic mechanisms for neurodegenerative disease are induced by specific conformations of Aβ intermediates. The efforts to understand the diverse intermediate forms of amyloid oligomers have been focused on understanding the aggregation mechanism of specific morphologies for Aβ intermediates. However, these are still not easy tasks to be accomplished because the diverse conformations of Aβ intermediates can be altered during the aggregation process, even though the same Aβ monomers are present. Thus, efforts to reveal the conformational change mechanism could be a fundamental process to understand the formation of diverse Aβ intermediate conformations. Here, we evaluate the conformational characteristics of Aβ17–42 fibrillar oligomers in different environments according to the length. We observed that Aβ fibrillar oligomers optimize their inherent hydrogen bonds and configurational entropy to stabilize their structure according to the simulation time and their length increase. In addition, we revealed the role of the expressed vibration mode shape in the fibrillar oligomers′ elongation and deformation processes. Our results suggest that limitations in amyloid oligomer growth and transformations of their morphologies can be regulated and controlled by modifying the vibration features.
Polymer‐Brush‐Grafted Mesoporous Silica Nanoparticles for Triggered Drug Delivery
Authors: Zhang Li , Bei Ho Pan , Piao Yun , Wang Yufeng , Yang Mo , Zhao Xin 
Published: March 2018

AbstractMesoporous silica nanoparticles (MSNs) have been demonstrated to be one of the most promising drug‐delivery systems (DDSs) to transport a variety of drugs/biomolecules. Functionalization of MSN surfaces with responsive polymer brushes leads to intelligent and controllable drug‐delivery properties, that is, the encapsulated drugs/biomolecules will only be released upon certain stimuli including pH, temperature, light, enzyme, ultrasound, or redox, thus maximizing their therapeutic efficiency and minimizing side effects. These polymer brushes can also increase the stability and extend the release period of the loaded cargoes. This Minireview presents an overview of recent research progress on stimuli‐responsive controlled DDSs based on polymer‐brush‐grafted MSNs. Utilizing the switching abilities of the grafted responsive polymer brushes, the smart DDSs show great potential for biomedical applications, especially for cancer therapy.
Copper Affects the Location of Zinc in Bimetallic Ion‐Exchanged Mordenite
Authors: Reule Allen A. C. , Shen Jing , Semagina Natalia 
Published: March 2018

AbstractBimetallic ion exchange on a zeolite often impacts its catalytic properties compared to its monometallic counterparts. Here, we address the synergistic effect of simultaneous copper and zinc ion exchange on mordenite (MOR), as found earlier for dimethyl ether (DME) carbonylation. Samples with various Cu/Zn ratios were characterized by diffuse‐reflectance infrared Fourier‐transform spectroscopy (DRIFTS) in the 3600 and 720 cm−1 regions, pore distribution analysis through Ar physisorption, X‐ray photoelectron spectroscopy (XPS), temperature‐programmed reduction (TPR), and transmission electron microscopy (TEM). When ion‐exchanged alone, copper preferentially occupies 12‐membered rings, whereas zinc occupies 8‐membered rings. In bimetallic combinations, the zinc addition was found to prevent the copper from sintering into nanoparticles and to increase its coordination strength to the zeolite. At a Cu/Zn ratio of 0.25 (for MOR with Si/Al=6.5), copper promotes zinc ion exchange into 12‐membered rings, more specifically, into T4 sites that are known for the formation of the coke precursor in DME carbonylation on a MOR. The sites became blocked during the bimetallic ion exchange, leading to suppressed catalyst deactivation. The study contributes to the understanding of mutual ion effects in bimetallic exchanged zeolites and highlights the major role of copper as a governing factor in determining the location of co‐exchanged zinc on a MOR.
Polydopamine Particle‐Filled Shape‐Memory Polyurethane Composites with Fast Near‐Infrared Light Responsibility
Authors: Yang Li , Tong Rui , Wang Zhanhua , Xia Hesheng 
Published: March 2018

AbstractA new kind of fast near‐infrared (NIR) light‐responsive shape‐memory polymer composites was prepared by introducing polydopamine particles (PDAPs) into commercial shape‐memory polyurethane (SMPU). The toughness and strength of the polydopamine‐particle‐filled polyurethane composites (SMPU‐PDAPs) were significantly enhanced with the addition of PDAPs due to the strong interface interaction between PDAPs and polyurethane segments. Owing to the outstanding photothermal effect of PDAPs, the composites exhibit a rapid light‐responsive shape‐memory process in 60 s with a PDAPs content of 0.01 wt%. Due to the excellent dispersion and convenient preparation method, PDAPs have great potential to be used as high‐efficiency and environmentally friendly fillers to obtain novel photoactive functional polymer composites.
Visible‐Light‐Activated Black Organotitanias: How Synthetic Conditions Influence Their Structure and Photocatalytic Activity
Authors: Jiménez‐López Jesús , Linares Noemi , Serrano Elena , García‐Martínez Javier 
Published: March 2018

AbstractA series of low‐temperature, visible‐light‐activated black organotitanias were synthesised through a sol–gel strategy that allowed the in situ incorporation of p‐phenylenediamine (PPD) into the framework of anatase nanoparticles. The effect of the synthetic conditions on the crystalline structure and photocatalytic activity of these materials was assessed by several characterisation techniques, which revealed a small crystalline domain size (4.6–5.5 nm), effective incorporation of PPD inside the nanoparticles, and a significant reduction in the band gap of these materials (from 3.2 to 2.7–2.9 eV). A systematic study of the synthetic parameters also allowed a significant reduction of the solvent used for the preparation of these black organotitanias (20‐fold), as well as the crystallisation time, without compromising the structural properties and photocatalytic activity of these materials. The organotitanias with the highest PPD content and high crystallinity result in the best performing materials in the photocatalytic degradation of rhodamine 6G under both UV‐ and visible‐light irradiation.