bluuebunny/crossref_metadata_2025_split huggingface dataset:
Asymmetrical Fluorene[2,3‐b]benzo[d]thiophene Derivatives: Synthesis, Solid‐State Structures, and Application in Solution‐Processable Organic Light‐Emitting Diodes
Authors: Du Chunyan , Ye Shanghui , Chen Jianming , Guo Yunlong , Liu Yunqi , Lu Kun , Liu Ying , Qi Ting , Gao Xike , Shuai Zhigang , Yu Gui 
Published: July 2009

AbstractA series of novel asymmetrical fused compounds containing the backbone of fluorene[2,3‐b]benzo[d]thiophene (FBT) were effectively synthesized and fully characterized. Single‐crystal X‐ray studies demonstrated that the length of the substituent side chains greatly affects the solid‐state packing of the obtained fused compounds. DFT, photophysical, and electrochemical studies all showed that the FBTs have large band gaps, low‐lying HOMO energy levels, and therefore good stability toward oxidation. Moreover, the substituents strongly influence the fluorescence properties of the resulting FBT derivatives. The di‐n‐hexyl compound exhibits intense fluorescence in solution with the highest quantum yield of up to 91 %. Solution‐processed green phosphorescent organic light‐emitting diodes with the di‐n‐butyl derivative as the host material exhibited a maximum brightness of 14 185 cd m−2 and a luminescence efficiency of 12 cd A−1.
Photochemistry of Cyclic Trisilanes: “Spring‐Loaded” Precursors to Methylphenylsilylene
Authors: Moiseev Andrey G. , Coulais Eugénie , Leigh William J. 
Published: July 2009

AbstractTwo new cyclic trisilanes containing a SiMePh moiety in the central position have been synthesized, and their photochemistries studied by steady‐state and laser flash photolysis methods. The yield of the transient silylene SiMePh increases at the expense of that of the corresponding cyclic silene derivative (formed by photochemical 1,3‐silyl migration into the phenyl ring) as the ring size is decreased from 7 to 6, facilitating the direct detection of the silylene by laser flash photolysis. The UV/Vis spectrum of SiMePh in hexanes solution (λmax=270, 505 nm) and absolute rate constants for its reaction with methanol, triethylsilane, a terminal alkene, alkyne, and two aliphatic dienes at 25 °C are reported.
Striking Reactivity of a Stable, Zwitterionic Silylene Towards Substituted Diazomethanes, Azides, and Isocyanides
Authors: Xiong Yun , Yao Shenglai , Driess Matthias 
Published: July 2009

AbstractThe reactivity of the zwitterionic N‐heterocyclic silylene (NHS) LSi: 1 (L=ArNC(Me)CHC(CH2)NAr, Ar=2,6‐iPr2C6H3), towards diphenyldiazomethane (Ph2CN2), trimethylsilyl azide (Me3SiN3), and cyclohexyl isocyanide (C6H11NC) is reported. The addition of Ph2CN2 to 1 leads to the diiminylsilane LSi(NCPh2)2 2 (80 % yield), whereas the treatment of 1 with Me3SiN3 gives the spirobicyclic silatetrazoline LSi(NNSiMe3)2 3 (67 % yield), and addition of C6H11NC gives the silyl cyanide LSi(R)CN (R=cyclohexyl) 4 (32 % yield) along with the unexpected azasilacyclobutane 5 (41 % yield). The novel compounds were fully characterized by 1H, 13C, and 29Si NMR spectroscopy, ESIMS, elemental analysis, and single‐crystal X‐ray diffraction.
Combination of Variant and Microvascular Angina
Authors: Infusino Fabio , Lanza Gaetano A. , Sestito Alfonso , Sgueglia Gregory A. , Crea Filippo , Maseri Attilio 
Published: July 2009

AbstractPrinzmetal's variant angina (VA) and cardiac syndrome X (CSX) are two distinct, usually easily recognizable, forms of angina syndromes, caused by epicardial spasm, usually responsible for transient transmural myocardial ischemia at rest and by coronary microvascular dysfunction (CMVD), usually responsible for effort induced subendocardial ischemia, respectively. In this article we report clinical evidence in three patients of the simultaneous occurrence of angina episodes typical of both VA and CSX, suggesting that common pathogenetic factors may be responsible for clinical manifestations both of functional macrovascular and microvascular coronary artery abnormalities in some angina patients. Copyright © 2009 Wiley Periodicals, Inc.
The origins and present status of the radio wave controversy in NMR
Authors: Hoult D.I. 
Published: July 2009

AbstractThe origins, history, and present status of the controversy surrounding a quantum description of the NMR signal as being due to radio waves are traced. With the Principle of Relativity and Coulomb's Law as formal starting points and the minimum of mathematics needed for understanding, the derivation of a classical electromagnetic theory of signal reception is first given. The agreement between that classical theory and a recent NMR experiment is then presented, leading to proof that, except for the highest field imaging experiments, there is no significant contribution of radio waves to the signal. Attention is drawn to the very different properties of the near and far energy, momenta, and fields inherent in the derivation. The role of the Correspondence Principle in formulating a quantum description is then emphasized and it is shown that the standard NMR interpretation of Dicke's theory of coherent spontaneous emission—that the latter is responsible for the NMR signal—cannot be correct. Finally, the author speculates on some of the intriguing relationships found in the classical electrodynamics of NMR signal reception and attempts to relate them to a common quantum electrodynamic precept of near field interaction: that the free induction decay voltage present at the terminals of an open‐circuit receiving coil is based on an exchange of virtual photons between the nuclei in a sample and the free electrons in a receiving coil. © 2009 Crown in the right of Canada. Concepts Magn Reson Part A 34A: 193–216, 2009.
Morphology of retinal ganglion cells in the ferret (Mustela putorius furo)
Authors: Isayama Tomoki , O'Brien Brendan J. , Ugalde Irma , Muller Jay F. , Frenz Aaron , Aurora Vikas , Tsiaras William , Berson David M. 
Published: July 2009

AbstractThe ferret is the premiere mammalian model of retinal and visual system development, but the spectrum and properties of its retinal ganglion cells are less well understood than in another member of the Carnivora, the domestic cat. Here, we have extensively surveyed the dendritic architecture of ferret ganglion cells and report that the classification scheme previously developed for cat ganglion cells can be applied with few modifications to the ferret retina. We confirm the presence of alpha and beta cells in ferret retina, which are very similar to those in cat retina. Both cell types exhibited an increase in dendritic field size with distance from the area centralis (eccentricity) and with distance from the visual streak. Both alpha and beta cell populations existed as two subtypes whose dendrites stratified mainly in sublamina a or b of the inner plexiform layer. Six additional morphological types of ganglion cells were identified: four monostratified cell types (delta, epsilon, zeta, and eta) and two bistratified types (theta and iota). These types closely resembled their counterparts in the cat in terms of form, relative field size, and stratification. Our data indicate that, among carnivore species, the retinal ganglion cells resemble one another closely and that the ferret is a useful model for studies of the ontogenetic differentiation of ganglion cell types. J. Comp. Neurol. 517:459–480, 2009. © 2009 Wiley‐Liss, Inc.
Afferent and efferent projections of the central caudal nidopallium in the pigeon (Columba livia)
Authors: Atoji Yasuro , Wild J. Martin 
Published: July 2009

AbstractThe central caudal nidopallium (NCC) is a large subdivision of the nidopallium in the pigeon brain, but its connectional anatomy is unknown. Here, we examined the connections of NCC by using tract‐tracing methods. Injections of cholera toxin B‐chain (CTB) in NCC labeled many neurons within NCC. Outside NCC, many labeled neurons were found in the dorsal intermediate mesopallium and medialmost part of the medial intermediate nidopallium, with a few in the intermediate (AI) and medial (AM) arcopallium. In the thalamus, labeled neurons were located in the subrotundal nucleus, the shell region of nucleus ovoidalis, and the caudal part of the dorsolateral posterior thalamic nucleus. Injections of biotinylated dextran amine (BDA) in NCC labeled many fibers running rostrocaudally within NCC. Some of these terminated in the dorsal intermediate mesopallium, but the size of the terminal field was smaller than the region of the dorsal intermediate mesopallium that provided the projection to NCC. NCC sent numerous efferents to AI and AM but few to the thalamus. In contrast, after CTB injections in the dorsal intermediate mesopallium, a few neurons were labeled in NCC, but, after BDA injections in the dorsal intermediate mesopallium, large numbers of labeled fibers were seen to project widely throughout NCC. These findings indicate that the flow of information is predominantly from the dorsal intermediate mesopallium to NCC and from there to the arcopallium (AI and AM). The arcopallial outflow to the medial hypothalamus could imply that NCC is involved in neuroendocrine and autonomic functions and is limbic in nature. J. Comp. Neurol. 517:350–370, 2009. © 2009 Wiley‐Liss, Inc.
Purkinje cell compartmentation of the cerebellum of microchiropteran bats
Authors: Kim Ji‐Young , Marzban Hassan , Chung Seung‐Hyuk , Watanabe Masahiko , Eisenman Leonard M. , Hawkes Richard 
Published: July 2009

AbstractTransverse boundaries divide the mammalian cerebellar cortex into transverse zones, and within each zone the cortex is further subdivided into a symmetrical array of parasagittal stripes. This topography is highly conserved across the Mammalia. Bats have a remarkable cerebellum with presumed adaptations to flight and to echolocation, but nothing is known of its compartmentation. We have therefore used two Purkinje cell compartmentation antigens, zebrin II/aldolase C and phospholipase Cβ4, to reveal the topography of the cerebellum in microchiropteran bats. Three species of bat were studied, Lasiurus cinereus, Lasionycteris noctivagans, and Eptesicus fuscus. A reproducible pattern of zones and stripes was revealed that is similar across the three species. The architecture of the bat cerebellum conforms to the ground plan of other mammals. However, two exceptions to the highly conserved mammalian architectural plan were revealed. First, many Purkinje cells in lobule I express zebrin II. A zebrin II‐immunopositive lobule I has not been seen previously in mammals but is characteristic of the avian cerebellum. Second, lobules VI–VII comprise the large central zone. Within the central zone two subdomains are evident, a small anterior subdomain (lobule VI) in which Purkinje cells are predominantly zebrin II‐immunopositive/PLCβ4‐immunonegative, as in other mammals, and a posterior subdomain (lobule VII), in which alternating zebrin II/phospholipase Cβ4 stripes are prominent. J. Comp. Neurol. 517:193–209, 2009. © 2009 Wiley‐Liss, Inc.
Distribution of high‐conductance calcium‐activated potassium channels in rat vestibular epithelia
Authors: Schweizer Felix E. , Savin David , Luu Cindy , Sultemeier David R. , Hoffman Larry F. 
Published: July 2009

AbstractVoltage‐ and calcium‐activated potassium channels (BK) are important regulators of neuronal excitability. BK channels seem to be crucial for frequency tuning in nonmammalian vestibular and auditory hair cells. However, there are a paucity of data concerning BK expression in mammalian vestibular hair cells. We therefore investigated the localization of BK channels in mammalian vestibular hair cells, specifically in rat vestibular neuroepithelia. We find that only a subset of hair cells in the utricle and the crista ampullaris express BK channels. BK‐positive hair cells are located mainly in the medial striolar region of the utricle, where they constitute at most 12% of hair cells, and in the central zone of the horizontal crista. A majority of BK‐positive hair cells are encapsulated by a calretinin‐positive calyx defining them as type I cells. The remainder are either type I cells encapsulated by a calretinin‐negative calyx or type II hair cells. Surprisingly, the number of BK‐positive hair cells in the utricle peaks in juvenile rats and declines in early adulthood. BK channels were not found in vestibular afferent dendrites or somata. Our data indicate that BK channel expression in the mammalian vestibular system differs from the expression pattern in the mammalian auditory and the nonmammalian vestibular system. The molecular diversity of vestibular hair cells indicates a functional diversity that has not yet been fully characterized. The predominance of BK‐positive hair cells within the medial striola of juvenile animals suggests that they contribute to a scheme of highly lateralized coding of linear head movements during late development. J. Comp. Neurol. 517:134–145, 2009. © 2009 Wiley‐Liss, Inc.
Treadmill training enhances axon regeneration in injured mouse peripheral nerves without increased loss of topographic specificity
Authors: English Arthur W. , Cucoranu Delia , Mulligan Amanda , Sabatier Manning 
Published: July 2009

AbstractWe investigated the extent of misdirection of regenerating axons when that regeneration was enhanced by using treadmill training. Retrograde fluorescent tracers were applied to the cut proximal stumps of the tibial and common fibular nerves 2 or 4 weeks after transection and surgical repair of the mouse sciatic nerve. The spatial locations of retrogradely labeled motoneurons were studied in untreated control mice and in mice receiving 2 weeks of treadmill training, according to either a continuous protocol (10 m/minute, 1 hour/day, 5 days/week) or an interval protocol (20 m/minute for 2 minutes, followed by a 5‐minute rest, repeated four times, 5 days/week). More retrogradely labeled motoneurons were found in both treadmill‐trained groups. The magnitude of this increase was as great as or greater than that found after using other enhancement strategies. In both treadmill‐trained groups, the proportions of motoneurons labeled from tracer applied to the common fibular nerve that were found in spinal cord locations reserved for tibial motoneurons in intact mice were no greater than in untreated control mice and significantly less than those found after electrical stimulation or chondroitinase treatment. Treadmill training in the first 2 weeks following peripheral nerve injury produces a marked enhancement of motor axon regeneration without increasing the propensity of those axons to choose pathways leading to functionally inappropriate targets. J. Comp. Neurol. 517:245–255, 2009. © 2009 Wiley‐Liss, Inc.
Increased levels of NMDA receptor NR2A subunits at pre‐ and postsynaptic sites of the hippocampal CA1: An early response to conditional double knockout of presenilin 1 and 2
Authors: Aoki Chiye , Lee Joyce , Nedelescu Hermina , Ahmed Tunazzina , Ho Angela , Shen Jie 
Published: July 2009

AbstractGreater than 90% of familial Alzheimer's disease (AD) is linked to mutations of presenilin (PS), and the loss of PS function altogether within mouse brains by conditional double knockout of the PS 1 and 2 genes (PS‐cDKO) leads to age‐dependent emergence of AD phenotypes, including neurodegeneration and reduced synaptic plasticity in the hippocampal CA1. The goal of our study was to identify the ultrastructural and molecular changes at synapses in the hippocampal CA1 of this PS‐cDKO mouse model of AD. We examined the asymmetric (excitatory) synapses formed on apical dendrites of CA1 pyramidal neurons at 2 months postnatal, an age when AD‐like symptoms emerge but brain morphology, as assessed by light microscopy, is still normal. Our quantitative electron microscopic analyses confirm that PS‐cDKO hippocampi at 2 months postnatal do not yet exhibit synapse losses or spine size alterations. However, immunocytochemistry reveals that the same region exhibits a 28% increase in the proportion of spines labeled for the NR2A subunits of NMDA receptors (NMDAR), with a 31% increase specifically at postsynaptic densities and a concomitant reduction of these subunits at nonsynaptic sites within spine heads. In contrast, no change in levels or the distribution pattern of NR2B subunit levels were detected within spine heads. Presynaptically, NR2A levels are elevated at axo‐spinous junctions and these may contribute to the timing‐dependent, long‐term depression. These observations point to an early‐onset trapping of NMDAR at synapses that are subtle but may underlie the reduced synaptic plasticity at 2 months of age and excitotoxicity at later stages. J. Comp. Neurol. 517:512–523, 2009. © 2009 Wiley‐Liss, Inc.
Inward rectifier channel, ROMK, is localized to the apical tips of glial‐like cells in mouse taste buds
Authors: Dvoryanchikov Gennady , Sinclair Michael S. , Perea‐Martinez Isabel , Wang Tong , Chaudhari Nirupa 
Published: July 2009

AbstractCells in taste buds are closely packed, with little extracellular space. Tight junctions and other barriers further limit permeability and may result in buildup of extracellular K+ following action potentials. In many tissues, inwardly rectifying K channels such as the renal outer medullary K (ROMK) channel (also called Kir1.1 and derived from the Kcnj1 gene) help to redistribute K+. Using reverse‐transcription polymerase chain reaction (RT‐PCR), we defined ROMK splice variants in mouse kidney and report here the expression of a single one of these, ROMK2, in a subset of mouse taste cells. With quantitative (q)RT‐PCR, we show the abundance of ROMK mRNA in taste buds is vallate > foliate > > palate > > fungiform. ROMK protein follows the same pattern of prevalence as mRNA, and is essentially undetectable by immunohistochemistry in fungiform taste buds. ROMK protein is localized to the apical tips of a subset of taste cells. Using tissues from PLCβ2‐GFP and GAD1‐GFP transgenic mice, we show that ROMK is not found in PLCβ2‐expressing type II/receptor cells or in GAD1‐expressing type III/presynaptic cells. Instead, ROMK is found, by single‐cell RT‐PCR and immunofluorescence, in most cells that are positive for the taste glial cell marker, Ectonucleotidase2. ROMK is precisely localized to the apical tips of these cells, at and above apical tight junctions. We propose that in taste buds, ROMK in type I/glial‐like cells may serve a homeostatic function, excreting excess K+ through the apical pore, and allowing excitable taste cells to maintain a hyperpolarized resting membrane potential. J. Comp. Neurol. 517:1–14, 2009. © 2009 Wiley‐Liss, Inc.
Effects of developmental age, brain region, and time in culture on long‐term proliferation and multipotency of neural stem cell populations
Authors: Gritti Angela , dal Molin Matteo , Foroni Chiara , Bonfanti Luca 
Published: July 2009

AbstractNeural stem cells (NSCs) in the murine subventricular zone (SVZ) niche allow life‐long neurogenesis. During the first postnatal month and throughout aging, the decrease of neuroblasts and the rise of astrocytes results in diminished neurogenesis and increased astrocyte:neuron ratio. Also, a different neurogenic activity characterizes the SVZ periventricular region (LV, lateral ventricle) as compared to its rostral extension (RE). In order to investigate whether and to what extent these physiological modifications may be ascribed to intrinsic changes of the endogenous NSC/progenitor features, we performed a functional analysis on NSCs isolated and cultured from LV and RE tissues at distinct postnatal stages that are marked by striking modifications to the SVZ niche in vivo. We evaluated the effect of age and brain region on long‐term proliferation and multipotency, and characterized the cell type composition of NSC‐derived progeny, comparing this make‐up to that of region‐ and age‐matched primary neural cultures. Furthermore, we analyzed the effect of prolonged in vitro expansion on NSC functional properties. We documented age‐ and region‐dependent differences on the clonogenic efficiency and on the long‐term proliferative capacity of NSCs. Also, we found age‐ and region‐dependent quantitative changes in the cell composition of NSC progeny (decreased quantity of neurons and oligodendrocytes; increased amount of astroglial cells) and these differences were maintained in long‐term cultured NSC populations. Overall, these data strengthen the hypothesis that age‐ and region‐dependent differences in neurogenesis (observed in vivo) may be ascribed to the changes in the intrinsic developmental program of the NSC populations. J. Comp. Neurol. 517:333–349, 2009. © 2009 Wiley‐Liss, Inc.
PICK1 expression in the Drosophila central nervous system primarily occurs in the neuroendocrine system
Authors: Jansen Anna M. , Nässel Dick R. , Madsen Kenneth L. , Jung Anita G. , Gether Ulrik , Kjaerulff Ole 
Published: July 2009

AbstractThe protein interacting with C kinase 1 (PICK1) protein was first identified as a novel binding partner for protein kinase C. PICK1 contains a membrane‐binding BAR domain and a PDZ domain interacting with many synaptic proteins, including the α‐amino‐3‐hydroxy‐5‐methylisoxazole‐4‐propionic acid (AMPA) receptor subunit GluR2 and the dopamine transporter. PICK1 is strongly implicated in GluR2 trafficking and synaptic plasticity. In mammals, PICK1 has been characterized extensively in cell culture studies. To study PICK1 in an intact system, we characterized PICK1 expression immunohistochemically in the adult and larval Drosophila central nervous system. PICK1 was found in cell bodies in the subesophageal ganglion, the antennal lobe, the protocerebrum, and the neuroendocrine center pars intercerebralis. The cell types that express PICK1 were identified using GAL4 enhancer trap lines. The PICK1‐expressing cells form a subpopulation of neurons. PICK1 immunoreactivity was neither detected in glutamatergic nor in dopaminergic neurons. Also, we observed PICK1 expression in only a few GABAergic neurons, located in the antennal lobe. In contrast, we detected robust PICK1 immunolabeling of peptidergic neurons in the neuroendocrine system, which express the transcription factor DIMM and the amidating enzyme peptidylglycine‐α‐hydroxylating monooxygenase (PHM). The PICK1‐positive cells include neurosecretory cells that produce the insulin‐like peptide dILP2. PICK1 expression in insulin‐producing cells also occurs in mammals, as it was also observed in a rat insulinoma cell line derived from pancreatic β‐cells. At the subcellular level, PICK1 was found in the perinuclear zone but surprisingly not in synaptic domains. We conclude that PICK1 may serve an important role in the neuroendocrine system both in insects and vertebrates. J. Comp. Neurol. 517:313–332, 2009. © 2009 Wiley‐Liss, Inc.