bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two separate, but interacting, neural systems for familiarity and novelty detection: A dual‐route mechanism
Authors: Kafkas Alexandros , Montaldi Daniela 
Published: January 2014

ABSTRACTIt has long been assumed that familiarity‐ and novelty‐related processes fall on a single continuum drawing on the same cognitive and neural mechanisms. The possibility that familiarity and novelty processing involve distinct neural networks was explored in a functional magnetic resonance imaging study (fMRI), in which familiarity and novelty judgments were made in contexts emphasizing either familiarity or novelty decisions. Parametrically modulated BOLD responses to familiarity and novelty strength were isolated in two separate, nonoverlapping brain networks. The novelty system involved brain regions along the ventral visual stream, the hippocampus, and the perirhinal and parahippocampal cortices. The familiarity system, on the other hand, involved the dorsomedial thalamic nucleus, and regions within the medial prefrontal cortex and the medial and lateral parietal cortex. Convergence of the two networks, treating familiarity and novelty as a single continuum was only found in a fronto‐parietal network. Finally, the orbitomedial prefrontal cortex was found to be sensitive to reported strength/confidence, irrespective of stimulus' familiarity or novelty. This pattern of results suggests a dual‐route mechanism supported by the existence of two distinct but interacting functional systems for familiarity and novelty. Overall, these findings challenge current assumptions regarding the neural systems that support the processing of novel and familiar information, and have important implications for research into the neural bases of recognition memory. © 2014 Wiley Periodicals, Inc.
Subregion‐specific decreases in hippocampal serotonin transporter protein expression and function associated with endophenotypes of depression
Authors: Tang Man , He Tao , Sun Xiao , Meng Qing‐Yan , Diao Yao , Lei Jie‐Yu , He Xiao‐Jing , Chen Lei , Sang Xiu‐Bo , Zhao Shulei 
Published: January 2014

ABSTRACTStress influences the development of depression, and depression is associated with structural and functional changes in the hippocampus. The current study sought to determine whether chronic corticosteroid (CORT) treatment influences serotonin transporter (5‐HTT) protein expression and function in the CA1, CA3, and dentate gyrus (DG) subregions of the hippocampus. Male CD‐1 mice were subcutaneously injected with CORT at a dose of 20 mg/kg once daily for 3 weeks. Behavioral state was assessed using sucrose preference, physical state of the coat, forced swimming test, and tail suspension test. We then determine 5‐HTT protein expression and synaptosomal 5‐HT uptake in the CA1, CA3 and DG subregions. CORT treatment induced anhedonia and behavioral despair, two core endophenotypes of clinical depression; 5‐HTT protein expression levels and synaptosomal 5‐HT uptake were both decreased in a subregion‐specific manner, with the greatest decrease observed in the DG, a moderate decrease in the CA3, and the CA1 showed no apparent change. In addition, a reduction in tissue mass was detected in the DG following the CORT treatment. These data indicate that subregion‐specific decreases in hippocampal 5‐HTT protein expression and function are associated with endophenotypes of depression. © 2014 Wiley Periodicals, Inc.
Characterizing context‐dependent differential firing activity in the hippocampus and entorhinal cortex
Authors: Prerau Michael J. , Lipton Paul A. , Eichenbaum Howard B. , Eden Uri T. 
Published: January 2014

ABSTRACTThe rat hippocampus and entorhinal cortex have been shown to possess neurons with place fields that modulate their firing properties under different behavioral contexts. Such context‐dependent changes in neural activity are commonly studied through electrophysiological experiments in which a rat performs a continuous spatial alternation task on a T‐maze. Previous research has analyzed context‐based differential firing during this task by describing differences in the mean firing activity between left‐turn and right‐turn experimental trials. In this article, we develop qualitative and quantitative methods to characterize and compare changes in trial‐to‐trial firing rate variability for sets of experimental contexts. We apply these methods to cells in the CA1 region of hippocampus and in the dorsocaudal medial entorhinal cortex (dcMEC), characterizing the context‐dependent differences in spiking activity during spatial alternation. We identify a subset of cells with context‐dependent changes in firing rate variability. Additionally, we show that dcMEC populations encode turn direction uniformly throughout the T‐maze stem, whereas CA1 populations encode context at major waypoints in the spatial trajectory. Our results suggest scenarios in which individual cells that sparsely provide information on turn direction might combine in the aggregate to produce a robust population encoding. © 2014 Wiley Periodicals, Inc.
Behavioral anxiolysis without reduction of hippocampal theta frequency after histamine application in the lateral septum of rats
Authors: Chee San‐San A. , Menard Janet L. , Dringenberg Hans C. 
Published: January 2014

ABSTRACTHippocampal theta activity is linked to various processes, including locomotion, learning and memory, and defense and affect (i.e., fear and anxiety). Interestingly, all classes of clinically effective anxiolytics, as well as experimental compounds that decrease anxiety in pre‐clinical animal models of anxiety, reduce the frequency of hippocampal theta activity elicited by stimulation of the reticular formation in freely behaving or anesthetized animals. In the present experiments, we found that bilateral histamine infusions (0.5 µg/hemisphere) into the lateral septum (LS) of rats decreased anxiety‐like responses in two models of anxiety, the elevated plus maze and novelty‐induced suppression of feeding test. Surprisingly, these same infusions significantly increased hippocampal theta frequency elicited by reticular stimulation in urethane‐anesthetized rats. In contrast to these findings, additional experiments showed that the clinically effective anxiolytic buspirone (40 mg/kg, i.p.) reduced theta frequency, confirming previous observations. Taken together, the dissociation of behavioral anxiolysis and theta frequency reduction noted here suggest that hippocampal theta frequency is not a direct index of anxiety levels in rodents. Further, the mechanisms underlying the behavioral and physiological effects elicited by histamine in the LS require further study. © 2014 Wiley Periodicals, Inc.
Five Freely Circulating miRNAs and Bone Tissue miRNAs Are Associated With Osteoporotic Fractures
Authors: Seeliger Claudine , Karpinski Katrin , Haug Alexander T , Vester Helen , Schmitt Andreas , Bauer Jan S , van Griensven Martijn 
Published: January 2014

ABSTRACT

Osteoporosis as a systemic skeletal disorder is characterized by increased bone fragility and the risk of fractures. According to the World Health Organization, osteoporosis is one of the 10 most common diseases and affects approximately 75 million people in Europe, the United States, and Japan. In this context, the identification of specific microRNA (miRNA) signatures is an important step for new diagnostic and therapeutic approaches. The focus of interest on miRNAs as biomarkers came with new publications identifying free circulating extracellular miRNAs associated with various types of cancer. This study aimed to identify specific miRNAs in patients with osteoporotic fractures compared with nonosteoporotic fractures. For the array analysis, miRNAs were isolated from the serum of 20 patients with hip fractures, transcribed, and the samples were pooled into 10 osteoporotic and 10 nonosteoporotic specimens. With each pool of samples, human serum and plasma miRNA PCR arrays were performed, which are able to identify 83 different miRNAs. Subsequently, a separate validation analysis of each miRNA found to be regulated in the array followed with miRNA samples isolated from the serum of 30 osteoporotic and 30 nonosteoporotic patients and miRNA samples isolated from the bone tissue of 20 osteoporotic and 20 nonosteoporotic patients. With the validation analysis of the regulated miRNAs, we identified 9 miRNAs, namely miR-21, miR-23a, miR-24, miR-93, miR-100, miR-122a, miR-124a, miR-125b, and miR-148a, that were significantly upregulated in the serum of patients with osteoporosis. In the bone tissue of osteoporotic patients, we identified that miR-21, miR-23a, miR-24, miR-25, miR-100, and miR-125b displayed a significantly higher expression. A total of 5 miRNAs display an upregulation both in serum and bone tissue. This study reveals an important role for several miRNAs in osteoporotic patients and suggested that they may be used as biomarkers for diagnostic purposes and may be a target for treating bone loss and optimizing fracture healing in osteoporotic patients. © 2014 American Society for Bone and Mineral Research.
Tl+ Showed Negligible Interaction with Inner Membrane Sulfhydryl Groups of Rat Liver Mitochondria, but Formed Complexes with Matrix Proteins
Authors: Korotkov Sergey M. , Brailovskaya Irina V. , Kormilitsyn Boris N. , Furaev Viktor V. 
Published: January 2014

ABSTRACTThe effects of Tl+ on protein sulfhydryl (SH) groups, swelling, and respiration of rat liver mitochondria (RLM) were studied in a medium containing TlNO3 and sucrose, or TlNO3 and KNO3 as well as glutamate plus malate, or succinate plus rotenone. Detected with Ellman's reagent, an increase in the content of the SH groups was found in the inner membrane fraction, and a simultaneous decline was found in the content of the matrix‐soluble fraction for RLM, incubated and frozen in 25–75 mM TlNO3. This increase was greater in the medium containing KNO3 regardless of the presence of Ca2+. It was eliminated completely for RLM injected in the medium containing TlNO3 and then washed and frozen in the medium containing KNO3. Calcium‐loaded RLM showed increased swelling and decreased respiration. These results suggest that a ligand interaction of Tl+ with protein SH groups, regardless of the presence of calcium, may underlie the mechanism of thallium toxicity.
Degree Conditions for Spanning Brooms
Authors: Chen Guantao , Ferrara Michael , Hu Zhiquan , Jacobson Michael , Liu Huiqing 
Published: January 2014

AbstractA broom is a tree obtained by subdividing one edge of the star an arbitrary number of times. In (E. Flandrin, T. Kaiser, R. Kužel, H. Li and Z. Ryjáček, Neighborhood Unions and Extremal Spanning Trees, Discrete Math 308 (2008), 2343–2350) Flandrin et al. posed the problem of determining degree conditions that ensure a connected graph G contains a spanning tree that is a broom. In this article, we give one solution to this problem by demonstrating that if G is a connected graph of order with , then G contains a spanning broom. This result is best possible.
Microscopic analysis of the localization of two chlorin‐based photosensitizers in OSC19 tumors in the mouse oral cavity
Authors: van Leeuwen–van Zaane Floor , van Driel Pieter B.A.A. , Gamm Ute A. , Snoeks Thomas J.A. , de Bruijn Henriëtte S. , van der Ploeg–van den Heuvel Angelique , Löwik Clemens W.G.M. , Sterenborg Henricus J.C.M. , Amelink Arjen , Robinson Dominic J. 
Published: January 2014

Background and ObjectiveThe effect of photodynamic therapy (PDT) is dependent on the localization of photosensitizer in the treatment volume at the time of illumination. Investigation of photosensitizer pharmacokinetics in and around the treatment volume aids in determining the optimal drug light interval for PDT.Materials and MethodsIn this paper we have investigated the distribution of the photosensitizers chlorin e6 and Bremachlorin in the oral squamous cell carcinoma cell‐line OSC19‐Luc‐Gfp in a tongue tumor, tumor boundary, invasive tumor boundary, and normal tongue tissue by the use of confocal microscopy of frozen sections. Tongues were harvested at t = [3, 4.5, 6, 24, 48] hours after injection.ResultsBoth photosensitizers showed a decreasing fluorescence with increasing incubation time, and at all time points higher fluorescence was measured in tumor boundary than in tumor itself. For short incubation times, a higher fluorescence intensity was observed in the invasive tumor border and normal tissue compared to tumor tissue. Bremachlorin showed a small increase in tumor to normal ratio at 24 and 48 hours incubation time. Ce6 was undetectable at 48 hours. We did not find a correlation between photosensitizer localization and the presence of vasculature.ConclusionThe modest tumor/tumor boundary to normal selectivity of between 1.2 and 2.5 exhibited by Bremachlorin 24 and 48 hours after administration may allow selective targeting of tongue tumors. Further studies investigating the relationship between Bremachlorin concentration and therapeutic efficacy PDT with long incubation times are warranted. Lasers Surg. Med. 46:224–234, 2014. © 2013 Wiley Periodicals, Inc.
A New Thermosensitive Poly(N‐propionyl‐aspartic acid/ethylene glycol) with No Cytotoxicity and Tunable UCST
Authors: Di Yingying , Ma Xin , Li Chunxiu , Liu Hongmei , Fan Xueying , Wang Meng , Deng Heying , Jiang Ting , Yin Ziming , Deng Kuilin 
Published: January 2014

A new thermosensitive poly(N‐propionyl‐aspartic acid/ethylene glycol) (PPAE) with no cytotoxicity and an upper critical solution temperature (UCST) is synthesized by polycondensation of l‐aspartic acid and ethylene glycol. The chemical structures of the monomer and polymer are confirmed by FTIR and 1H NMR spectroscopy, and by elemental analysis measurements. Turbidimetric measurements indicate that PPAE shows a reversible UCST phase transition at 1.5–37.6 °C in pure water or an alcohol/water mixture. The UCST can be facilely tuned via changing the content of alcohol in water or the normal saline. Moreover, the survival rate of HeLa cells to PPAE is close to 100% within 48 h, demonstrating no cytotoxicity. Such aspartic acid‐based polymers with tunable thermosensitivity could be useful in the biomedical field.
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Star‐Like Dextran‐graft‐(polyacrylamide‐co‐polyacrylic acid) Copolymers
Authors: Kutsevol Nataliya , Bezuglyi Mykola , Bezugla Tetiana , Rawiso Michel 
Published: January 2014

SummaryStar‐like dextran‐graft‐(polyacrylamide‐co‐polyacrylic acid) (D‐g‐(PAA‐co‐PAAc) copolymers in a salt form were obtained by alkaline hydrolysis of Dextran‐graft‐Polyacrylamide (D‐g‐PAA) samples. The internal structure of D‐g‐PAA in solution predetermined the reaction course and the conversion degree depended upon the initial architecture of macromolecules. It was shown that macromolecules of D‐g‐(PAA‐co‐PAAc) acquired extended conformation because grafted chains became greatly straightened when charged functional groups appeared. No polyelectrolyte effect for synthesized D‐g‐(PAA‐co‐PAAc) samples was registered. Star‐like polyelectrolytes were proved to be more efficient matrices in comparison with linear anionic Polyacrylamide for silver nanoparticle in situ synthesis.
Controlled Aggregation of Biopolymer‐Wrapped Carbon Nanotubes in Aqueous Suspension, Induced by Cationic Porphyrin
Authors: Zarudnev E. S. , Karachevtsev V. A. 
Published: January 2014

SummaryUnusual aggregation of biopolymer‐wrapped single‐walled carbon nanotubes (SWCNTs) induced by cationic porphyrin meso‐tetrakis(4‐N‐methyl‐pyridyl)porphine (TMPyP4) in aqueous suspension has been studied by absorption spectroscopy and molecular dynamics simulation. After the addition of a small dose of TMPyP4 (10−6 M) into poly(rC):SWCNTs aqueous suspension, nanotubes begin to aggregate, but the aggregates are stable without precipitation during a few days. Spectral observations indicate that the porphyrin core stacked with π‐systems of the biopolymer:SWCNT hybrid and all nanotube species take part in this aggregate formation without any selection. Molecular dynamic simulation demonstrates that the stable complex consisting of two nanotubes can be formed when TMPyP4 molecules bound nanotubes both owing to π‐π stacking of the porphyrin core with the surface of one nanotube and with the oligonucleotide adsorbed onto another nanotube. TMPyP4 molecules not only couple the biopolymer:nanotube hybrids, but also they stitch polymer's strands wrapping around each nanotube resulting in continuous floatation of aggregates in water. It was shown that the aggregate is stable even at 373 K. At this temperature additional contacts between two neighbor's polymers appear which strengthen this aggregate too. The controlled aggregation of biopolymer‐wrapped carbon nanotubes can be employed at the fabrication of multifunctional supramolecular assemblies, photovoltaic cells and in biosensing.
Preparation of Hybrid Fe3O4/Poly(lactic‐co‐glycolic acid) (PLGA) Particles by Emulsion and Evaporation Method. Optimization of the Experimental Parameters
Authors: Pérez A. , Mijangos C. , Hernández R. 
Published: January 2014

SummaryThe incorporation of iron oxide nanoparticles into poly(lactic‐co‐glycolic) (PLGA) particles was carried out with an emulsion and evaporation method. To optimize the mean size and the particle size distribution of the particles, the following parameters were modulated: the molecular weight and the hydrolyzation degree of the surfactant, the concentration of the aqueous phase and the stirring rate. Samples were characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS) and thermogravimetric analysis (TGA).
Cognitive impairment in rapid‐onset dystonia‐parkinsonism
Authors: Cook Jared F. , Hill Deborah F. , Snively Beverly M. , Boggs Niki , Suerken Cynthia K. , Haq Ihtsham , Stacy Mark , McCall W. Vaughn , Ozelius Laurie J. , Sweadner Kathleen J. , Brashear Allison 
Published: January 2014

ABSTRACTRapid‐onset dystonia‐parkinsonism (RDP) is caused by mutations in the ATP1A3 gene. This observational study sought to determine if cognitive performance is decreased in patients with RDP compared with mutation‐negative controls. We studied 22 familial RDP patients, 3 non‐motor‐manifesting mutation‐positive family members, 29 mutation‐negative family member controls in 9 families, and 4 unrelated RDP patients, totaling 58 individuals. We administered a movement disorder assessment, including the Burke‐Fahn‐Marsden Dystonia Rating Scale (BFMDRS) and the Unified Parkinson's Disease Rating Scale (UPDRS) and a cognitive battery of memory and learning, psychomotor speed, attention, and executive function. The cognitive battery was designed to evaluate a wide range of functions; recognition memory instruments were selected to be relatively pure measures of delayed memory, devoid of significant motor or vocal production limitations. Comparisons of standardized cognitive scores were assessed both with and without controlling for psychomotor speed and similarly for severity of depressive symptoms. A majority of RDP patients had onset of motor symptoms by age 25 and had initial symptom presentation in the upper body (face, mouth, or arm). Among patients, the BFMDRS (mean ± SD, 52.1 ± 29.5) and UPDRS motor subscore (29.8 ± 12.7) confirmed dystonia‐parkinsonism. The affected RDP patients performed more poorly, on average, than mutation‐negative controls for all memory and learning, psychomotor speed, attention, and executive function scores (all P ≤ 0.01). These differences persisted after controlling for psychomotor speed and severity of depressive symptoms. Impaired cognitive function may be a manifestation of ATP1A3 mutation and RDP. © 2014 International Parkinson and Movement Disorder Society
Abundant explicit exact solutions to the generalized nonlinear Schrödinger equation with parabolic law and dual‐power law nonlinearities
Authors: Zheng Xiaoxiao , Shang Yadong 
Published: January 2014

AbstractThis paper is concerned with the generalized nonlinear Schrödinger equation with parabolic law and dual‐power law. Abundant explicit and exact solutions of the generalized nonlinear Schrödinger equation with parabolic law and dual‐power law are derived uniformly by using the first integral method. These exact solutions are include that of extended hyperbolic function solutions, periodic wave solutions of triangle functions type, exponential form solution, and complex hyperbolic trigonometric function solutions and so on. The results obtained confirm that the first integral method is an efficient technique for analytic treatment of a wide variety of nonlinear systems of partial DEs. Copyright © 2014 John Wiley & Sons, Ltd.
A new look at the construct validity of the K6 using Rasch analysis
Authors: Khan Asaduzzaman , Chien Chi‐Wen , Burton Nicola W. 
Published: January 2014

AbstractThe Kessler six‐item psychological distress (K6) scale is widely used to screen for mental disorders; however, information is lacking on the rating scale performance or dimensionality structure of the scale. This study used a population based sample (n = 7596) to evaluate the construct validity of the K6 scale using Rasch partial credit analysis. The analysis showed that almost all of the five‐point rating scales in the K6 items were used appropriately to differentiate psychological distress of the study participants. The analysis provided evidence of unidimensionality of the scale, although items 1 (so sad) and 3 (restless or fidgety) might offer a potential second off‐dimensional component. All items appeared to fit the Rasch model's expectation as demonstrated by the acceptable item fit statistics. The study participants demonstrated valid response patterns when answering K6 items, except for some who were younger or had higher psychological distress. This study using Rasch analysis confirms the construct validity of the K6 scale and suggests that the K6 is a useful and valid instrument for assessing psychological distress in the mid‐aged general population. Further research can facilitate better understanding about the unidimensionality of the scale. Copyright © 2014 John Wiley & Sons, Ltd.
Analysis of proton‐density bias corrections based on T1 measurement for robust quantification of water content in the brain at 3 Tesla
Authors: Abbas Zaheer , Gras Vincent , Möllenhoff Klaus , Keil Fabian , Oros‐Peusquens Ana‐Maria , Shah Nadim J. 
Published: January 2014

PurposeEstimating tissue water content using high field MRI, such as 3 Tesla (T), is challenging due to the difficulty in dissociating the radio frequency inhomogeneity pattern from the signal arising from tissue intrinsic proton density (PD) variations. To overcome this problem the longitudinal relaxation time T1 can be combined with an initial guess of the PD to yield the desired PD bias correction. However, it is necessary to know whether T1 effects, i.e., any effect contributing to T1 while being independent of tissue hydration, influence the estimated correction.MethodsTwenty‐five healthy subjects underwent a quantitative 3T MRI protocol enabling acquisition of 64 slices with 1 mm in‐plane resolution and 2 mm slice thickness in 14 min. Influence of T1 effects on the estimated water content map is evaluated using a dedicated method including T1 and T2* information and region of interest‐based water content values are compared with the literature.ResultsOur analysis indicates that the PD bias correction based on T1 is largely insensitive to T1 effects. Besides, water content results are in good agreement with literature values obtained at 1.5T.ConclusionThis study demonstrates the applicability of a PD bias correction based on T1 to yield tissue water content at 3T. Magn Reson Med 72:1735–1745, 2014. © 2014 Wiley Periodicals, Inc.