bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of high-performance holographic gratings using siloxane-containing mesogenic compounds
Authors: Kawakami Yusuke , He Man , Cho Yeong Hee
Published: September 2006

Fine holographic gratings were fabricated using siloxane- and mesogen-containing compounds. A grating with 40 % diffraction efficiency was formed with 10 wt % non-liquid-crystalline 4-methoxyphenyl 4-[4-(pentamethyldisiloxanyl)butoxy]benzoate and trimethylolpropane triacrylate. 4-Methoxyphenyl 4-[4-(1,1,3,3,5,5,5-heptamethyltrisiloxan-1-yl)butoxy]-benzoate gave 50 % diffraction efficiency and angular selectivity of 5°.

Siloxane-containing liquid-crystalline compounds were also effective in fabricating fine gratings. These compounds induced distinct phase separation over a concentration range from 6 to 20 wt % in the formation of holographic gratings. The use of ring-opening polymerizable bifunctional epoxides as one of the reactive cross-linking matrix components, together with penta- or tetra-acrylate initiated by 3,3'-carbonylbis(7-diethylaminocoumarin)diphenyliodonium hexafluorophosphate, greatly improved the diffraction efficiency.

Fine gratings with 70 and 78 % diffraction efficiency and angular selectivity of 5° were formed with 10 wt % 4-cyano-4'-[(5-heptamethyltrisiloxan-1-yl)pentyloxy]-biphenyl and 4-cyanophenyl 4-[(5-heptamethyltrisiloxan-1-yl)pentyloxy]benzoate using pentaerythritol pentaacrylate-neopentylglycol diglycidyl ether-tripropylene glycol diacrylate (4:5:1) as the polymer matrix component.
Unexpected and intriguing reactivity of α-imino esters and iminium salts
Authors: Shimizu Makoto
Published: September 2006

An intriguing umpolung of the reactivity of imines possessing electron-withdrawing groups was observed. For example, N-alkylation-coupling reaction of the imines derived from glyoxylates was conducted with dialkylaluminum chloride in acetonitrile to give N-monoalkylated 1,2-diamines in good yields. On treatment of various α-imino esters with organoaluminum reagents and allyltributyltin in the presence of benzoyl peroxide (BPO), the tandem reaction proceeded to give the N-alkylation/C-allylation products in good yields. Diethyl 2-[N-(p-methoxyphenyl)imino]-malonate underwent amination reactions with alkyl Grignard reagents to give N-alkylation products in good yields. The obtained N-alkylation products were readily converted into N-alkyl-p-anisidines by the oxidative removal of the malonate moiety. In order to enhance the reactivity of imines, an iminium salt was prepared using the oxidation of amino ketene silyl acetal with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), and the subsequent nucleophilic addition to this iminium species proceeded to afford α-amino esters in good yields.
Dinitrosyl rhenium complexes for ring-opening metathesis polymerization (ROMP)
Authors: Frech Christian Manfred , Blacque Olivier , Berke Heinz
Published: September 2006

The treatment of benzene solutions of the cations [Re(NO)2(PR3)2][BArF
4] (R = Cy and R =
i
Pr; [BArF
4] = tetrakis{3,5-bis(trifluoromethyl)phenyl}borate) with phenyldiazomethane afforded the moderately stable cationic rhenium(I) benzylidene dinitrosyl bis(trialkyl) phosphine complexes as [BArF
4]- salts in good yields. The cationic rhenium dinitrosyl bisphosphine complexes catalyze the ring-opening metathesis polymerization (ROMP) of highly strained nonfunctionalized cyclic olefins to give polymers with relatively high polydispersity indices, high molecular weights, and Z configurations of the double bonds in the polymer chain backbones of over 80 %. The benzylidene derivatives are almost inactive in ROMP catalysis with norbornene and in olefin metathesis. NMR experiments gave first hints for the initial formation of carbene complexes when [Re(NO)2(PR3)2][BArF
4] was treated with norbornene. The carbene formation is initiated by an unique reaction sequence where the cleavage of the strained olefinic bond starts with phosphine migration forming a cyclic ylid carbene complex. The [2+2] addition of a norbornene molecule to the Re=C bond leads to the rhenacyclobutane complex, which is expected to be converted into an iminate complex by attack of the ylid function onto one of the NNO atoms followed by Wittig-type phosphine oxide elimination. The formation of phosphine oxide was confirmed by NMR spectroscopy. This species is thought to drive the ROMP metathesis with alternating rhenacyclobutane formations and cycloreversions. The proposed mechanism is supported by density functional theory (DFT) calculations.
Core-shell Si/C nanocomposite as anode material for lithium ion batteries
Authors: Zhang Tao , Fu Lijun , Gao Jie , Yang Lichun , Wu Yuping , Wu Hoqing
Published: September 2006

We report an effective method for the synthesis of a core-shell Si/C nanocomposite, and its application as anode material for lithium ion (Li-ion) batteries. Polyacrylonitrile (PAN)-coated Si nanoparticles are formed by emulsion polymerization, and this precursor is heat-treated under argon to generate a Si/C core-shell nanocomposite. The conductive carbon shell envelops the silicon nanoparticles and suppresses aggregation of the nanoparticles during cycling. Meanwhile, the carbon shell combines closely with the nanocores, and significantly enhances the kinetics of lithium intercalation and de-intercalation, as well as the apparent diffusion coefficient of Li-ions. Consequently, the core-shell Si/C nanocomposite exhibits better electrochemical performance than pure Si nanoparticles, indicating that this is a promising approach to improve cyclability and kinetics of nano-anode materials for Li-ion batteries.
Global Transcriptome Analysis of Genetically Identified Neurons in the Adult Cortex
Authors: Rossner Moritz J. , Hirrlinger Johannes , Wichert Sven P. , Boehm Christine , Newrzella Dieter , Hiemisch Holger , Eisenhardt Gisela , Stuenkel Carolin , von Ahsen Oliver , Nave Klaus-Armin
Published: September 2006

The enormous cellular complexity of the brain is a major obstacle for gene expression profiling of neurological disease models, because physiologically relevant changes of transcription in a specific neuronal subset are likely to be lost in the presence of other neurons and glia. We solved this problem in transgenic mice by labeling genetically defined cells with a nuclear variant of GFP. When combined with laser-directed microdissection, intact RNA from unfixed, freeze-dried sections can be isolated, which is a prerequisite for high-quality global transcriptome analysis. Here, we compared gene expression profiles between pyramidal motor neurons and pyramidal somatosensory neurons captured from layer V of the adult neocortex. One striking feature of motor neurons is the elevated expression of ribosomal genes and genes involved in ATP synthesis. This suggests a molecular adaptation of the upper motor neurons to longer axonal projections and higher electrical activity. These molecular signatures were not detected when cortical layers and microareas were analyzedin toto.

Additionally, we used microarrays to determine the global mRNA expression profiles of microdissected Purkinje cells and cellularly complex cerebellar cortex microregions. In summary, our analysis shows that cellularly complex targets lead to averaged gene expression profiles that lack substantial amounts of cell type-specific information. Thus, cell type-restricted sampling strategies are mandatory in the CNS. The combined use of a genetic label with laser-microdissection offers an unbiased approach to map patterns of gene expression onto practically any cell type of the brain.
Discrimination between the Enantiomers of Carvone and of Terpinen-4-ol Odorants in Normal Rats and Those with Lesions of the Olfactory Bulbs
Authors: McBride Kathleen , Slotnick Burton
Published: September 2006

We assessed (1) whether the enantiomers of terpinen-4-ol, odorants that activate nearly identical areas of the olfactory bulb, are more difficult to discriminate than those of carvone, odorants that activate different areas of the olfactory bulb, and (2) whether olfactory bulb lesions that disrupt the pattern of bulbar activation produced by these enantiomers degraded the ability of rats to discriminate between them. In psychophysical tests, normal rats discriminated between the enantiomers of terpinen-4-ol and of carvone equally well. Surgical lesions that removed the majority of bulbar glomeruli activated by these odorants (as demonstrated in previous olfactory bulb studies using intrinsic optical imaging and 2-deoxyglucose) resulted in increased detection thresholds but few or no deficits in discriminating between suprathreshold concentrations of the enantiomers. These results fail to confirm predictions based on 2-deoxyglucose maps of bulbar activity that enantiomers of terpinen-4-ol should be more difficult to discriminate than those of carvone and that the ability to discriminate between enantiomers of an odorant are based on differences in patterns of bulbar activation revealed in such maps.
Cytosolic Catechols Inhibit α-Synuclein Aggregation and Facilitate the Formation of Intracellular Soluble Oligomeric Intermediates
Authors: Mazzulli Joseph R. , Mishizen Amanda J. , Giasson Benoit I. , Lynch David R. , Thomas Steven A. , Nakashima Akira , Nagatsu Toshiharu , Ota Akira , Ischiropoulos Harry
Published: September 2006

Aberrant aggregation of α-synuclein (α-syn) to form fibrils and insoluble aggregates has been implicated in the pathogenic processes of many neurodegenerative diseases. Despite the dramatic effects of dopamine in inhibiting the formation of α-syn fibrils by stabilization of oligomeric intermediates in cell-free systems, no studies have examined the effects of intracellular dopamine on α-syn aggregation. To study this process and its association with neurodegeneration, intracellular catechol levels were increased to various levels by expressing different forms of tyrosine hydroxylase, in cells induced to form α-syn aggregates. The increase in the steady-state dopamine levels inhibited the formation of α-syn aggregates and induced the formation of innocuous oligomeric intermediates. Analysis of transgenic mice expressing the disease-associated A53T mutant α-syn revealed the presence of oligomeric α-syn in nondegenerating dopaminergic neurons that do contain insoluble α-syn. These data indicate that intraneuronal dopamine levels can be a major modulator of α-syn aggregation and inclusion formation, with important implications on the selective degeneration of these neurons in Parkinson's disease.
Structural Basis for Map Formation in the Thalamocortical Pathway of the Barrelless Mouse
Authors: Gheorghita Fulvia , Kraftsik Rudolf , Dubois Roger , Welker Egbert
Published: September 2006

Barrelless mice (BRL) homozygous for the BRL mutation that disrupts the gene coding for adenylyl cyclase type I on chromosome 11 lack spatial segregation of layer IV cortical cells and of the thalamocortical axons (TCAs) into barrel domains. Despite these morphological perturbations, a functional topographic map has been demonstrated. We reconstructed individual biocytin-injected TCAs from thalamus to barrel cortex in NOR (normal) and BRL mice to analyze to what extent the TCA arborization pattern and bouton distribution could explain the topographic representation of the whisker follicles. In BRL, the geometry of TCA is modified within layer IV as well as in infragranular layers. However, in both strains, the spatial distribution of TCA in layer IV reflects the spatial relationship of their cell bodies in the ventrobasal nucleus of the thalamus. The morphometric analysis revealed that TCAs of both strains have the same length, branch number, and number of axonal boutons in layer IV. However, in barrelless, the boutons are distributed within a larger tangential extent. Analysis of the distribution of boutons from neighboring thalamic neurons demonstrated the existence in layer IV of domains of high bouton density that in both strains equal the size and shape of individual barrels. We propose that the domains of high bouton density are at the basis of the whisker map in barrelless mice.
Locus Ceruleus Regulates Sensory Encoding by Neurons and Networks in Waking Animals
Authors: Devilbiss David M. , Page Michelle E. , Waterhouse Barry D.
Published: September 2006

Substantial evidence indicates that the locus ceruleus (LC)–norepinephrine (NE) projection system regulates behavioral state and state-dependent processing of sensory information. Tonic LC discharge (0.1–5.0 Hz) is correlated with levels of arousal and demonstrates an optimal firing rate during good performance in a sustained attention task. In addition, studies have shown that locally applied NE or LC stimulation can modulate the responsiveness of neurons, including those in the thalamus, to nonmonoaminergic synaptic inputs. Many recent investigations further indicate that within sensory relay circuits of the thalamus both general and specific features of sensory information are represented within the collective firing patterns of like-modality neurons. However, no studies have examined the impact of NE or LC output on the discharge properties of ensembles of functionally related cells in intact, conscious animals. Here, we provide evidence linking LC neuronal discharge and NE efflux with LC-mediated modulation of single-neuron and neuronal ensemble representations of sensory stimuli in the ventral posteriomedial thalamus of waking rats. As such, the current study provides evidence that output from the LC across a physiologic range modulates single thalamic neuron responsiveness to synaptic input and representation of sensory information across ensembles of thalamic neurons in a manner that is consistent with the well documented actions of LC output on cognition.
Na+, Cl−, and pH Dependence of the Human Choline Transporter (hCHT) inXenopusOocytes: The Proton Inactivation Hypothesis of hCHT in Synaptic Vesicles
Authors: Iwamoto Hideki , Blakely Randy D. , De Felice Louis J.
Published: September 2006

The recent cloning of the human choline transporter (hCHT) has allowed its expression inXenopuslaevisoocytes and the simultaneous measurement of choline transport and choline-induced current under voltage clamp. hCHT currents and choline transport are evident in cRNA-injected oocytes and significantly enhanced by the hCHT trafficking mutant L530A/V531A. The charge/choline ratio of hCHT varies from 10e/choline at −80 mV to 3e/choline at −20 mV, in contrast with the reported fixed stoichiometry of the Na+-coupled glucose transporter in the same gene family. Ion substitution shows that the choline uptake and choline-induced current are Na+and Cl−dependent; however, the reversal potential of the induced current suggests a Na+-selective mechanism, consigning Cl−to a regulatory role rather than a coupled, cotransported-ion role. The hCHT-specific inhibitor hemicholinium-3 (HC-3) blocks choline uptake and choline-induced current; in addition, HC-3 alone reveals a constitutive, depolarizing leak current through hCHT. We show that external protons reduce hCHT current, transport, and binding with a similar pKa of 7.4, suggesting proton titration of residue(s) that support choline binding and transport. Given the localization of the choline transporter to synaptic vesicles, we propose that proton inactivation of hCHT prevents acetylcholine and proton leakage from the acidic interior of cholinergic synaptic vesicles. This mechanism would allow cholinergic, activity-triggered delivery of silent choline transporters to the plasma membrane, in which normal pH would reactivate the transporters for choline uptake and subsequent acetylcholine synthesis.
Identification of a Novel Oligodendrocyte Cell Adhesion Protein Using Gene Expression Profiling
Authors: Nielsen Joseph A. , Maric Dragan , Lau Pierre , Barker Jeffery L. , Hudson Lynn D.
Published: September 2006

Oligodendrocytes undergo extensive changes as they differentiate from progenitors into myelinating cells. To better understand the molecular mechanisms underlying this transformation, we performed a comparative analysis using gene expression profiling of A2B5+oligodendrocyte progenitors and O4+oligodendrocytes. Cells were sort-purifiedex vivofrom postnatal rat brain using flow cytometry. Using Affymetrix microarrays, 1707 transcripts were identified with a more than twofold increase in expression in O4+oligodendrocytes. Many genes required for oligodendrocyte differentiation were upregulated in O4+oligodendrocytes, including numerous genes encoding myelin proteins. Transcriptional changes included genes required for cell adhesion, actin cytoskeleton regulation, and fatty acid and cholesterol biosynthesis. At the O4+stage, there was an increase in expression of a novel proline-rich transmembrane protein (Prmp). Localized to the plasma membrane, Prmp displays adhesive properties that may be important for linking the extracellular matrix to the actin cytoskeleton. Together, our results highlight the usefulness of this discovery-driven experimental strategy to identify genes relevant to oligodendrocyte differentiation and myelination.
Activation of Group II Metabotropic Glutamate Receptors Attenuates Both Stress and Cue-Induced Ethanol-Seeking and Modulates c-fosExpression in the Hippocampus and Amygdala
Authors: Zhao Yu , Dayas Christopher V. , Aujla Harinder , Baptista Marco A. S. , Martin-Fardon Rémi , Weiss Friedbert
Published: September 2006

Major precipitating factors for relapse to drug use are stress and exposure to drug-related environmental stimuli. Group II (mGlu2/3) metabotropic glutamate receptors (mGluRs) are densely expressed within circuitries mediating the motivating effects of stress and drug cues and, therefore, may participate in regulating drug-seeking linked to both of these risk factors. Thus, we tested the hypothesis that pharmacological activation of group II mGluRs modifies both stress- and cue-induced ethanol-seeking, using reinstatement models of relapse. In parallel, brain c-fosexpression was examined to identify neural substrates for the behavioral effects of group II mGluR activation. The selective mGlu2/3agonist LY379268 (1R,4R,5S,6R-2-oxa-4-aminobicyclo[3.1.0]hexane-4,6-dicarboxylate) (0.3, 1.0, and 3.0 mg/kg, s.c.) dose dependently blocked the recovery of extinguished ethanol-seeking induced by either footshock stress or ethanol-associated discriminative stimuli. These effects were accompanied by modulation of c-fosexpression in the hippocampus, central nucleus of the amygdala, bed nucleus of the stria terminalis, and medial parvocellular paraventricular nucleus of the hypothalamus. The results implicate group II mGluRs as a shared neuropharmacological substrate for ethanol-seeking elicited by both drug cues and stress and identify group II mGluRs as promising treatment targets for relapse prevention.
α-Internexin Is Structurally and Functionally Associated with the Neurofilament Triplet Proteins in the Mature CNS
Authors: Yuan Aidong , Rao Mala V. , Sasaki Takahiro , Chen Yuanxin , Kumar Asok , Veeranna  , Liem Ronald K. H. , Eyer Joel , Peterson Alan C. , Julien Jean-Pierre , Nixon Ralph A.
Published: September 2006

α-Internexin, a neuronal intermediate filament protein implicated in neurodegenerative disease, coexists with the neurofilament (NF) triplet proteins (NF-L, NF-M, and NF-H) but has an unknown function. The earlier peak expression of α-internexin than the triplet during brain development and its ability to form homopolymers, unlike the triplet, which are obligate heteropolymers, have supported a widely held view that α-internexin and neurofilament triplet form separate filament systems. Here, we demonstrate, however, that despite a postnatal decline in expression, α-internexin is as abundant as the triplet in the adult CNS and exists in a relatively fixed stoichiometry with these subunits. α-Internexin exhibits transport and turnover rates identical to those of triplet proteins in optic axons and colocalizes with NF-M on single neurofilaments by immunogold electron microscopy. α-Internexin also coassembles with all three neurofilament proteins into a single network of filaments in quadruple-transfected SW13vim(−) cells. Genetically deleting NF-M alone or together with NF-H in mice dramatically reduces α-internexin transport and content in axons throughout the CNS. Moreover, deleting α-internexin potentiates the effects of NF-M deletion on NF-H and NF-L transport. Finally, overexpressing a NF-H–LacZ fusion protein in mice induces α-internexin and neurofilament triplet to aggregate in neuronal perikarya and greatly reduces their transport and content selectively in axons. Our data show that α-internexin and the neurofilament proteins are functionally interdependent. The results strongly support the view that α-internexin is a fourth subunit of neurofilaments in the adult CNS, providing a basis for its close relationship with neurofilaments in CNS diseases associated with neurofilament accumulation.
Role of Megakaryoblastic Acute Leukemia-1 in ERK1/2-Dependent Stimulation of Serum Response Factor-Driven Transcription by BDNF or Increased Synaptic Activity
Authors: Kalita Katarzyna , Kharebava Giorgi , Zheng Jing-Juan , Hetman Michal
Published: September 2006

Serum response factor (SRF)-mediated transcription contributes to developmental and adult brain plasticity. Therefore, we investigated the role of a newly identified SRF coactivator, MKL1, in the regulation of SRF-driven transcription in rat forebrain neurons. MKL1 expression was found in newborn rat cortical or hippocampal neurons in culture as well as in adult rat forebrain. Immunostaining demonstrated constitutive nuclear localization of MKL1 in the CA1 region of the hippocampus, in the deep layers of the neocortex, and in cultured neurons. Overexpression of MKL1 in primary cortical neurons elevated SRF-driven transcription and enhanced its stimulation by BDNF. In addition, inhibition of endogenous MKL1 by overexpression of a dominant-negative MKL1 mutant or by small interfering RNA reduced BDNF activation of SRF-driven transcription. In neurons, endogenous MKL1 was associated with SRF-regulated chromatin regions of several endogenous genes including c-fos,JunB,Srf, andCyr61. BDNF activation of MKL1/SRF-driven transcription was dependent on the extracellular signal-regulated kinase 1/2 (ERK1/2) pathway, which also led to MKL1 phosphorylation. Finally, synaptic activity stimulation of SRF-driven transcription was reduced by inhibition of endogenous MKL1. Conversely, synaptic activity enhanced transcription by overexpressed MKL1. MKL1 regulation by synaptic activity was mediated through the NMDA receptor-activated ERK1/2. These results suggest that neuronal MKL1 contributes to SRF-regulated gene expression induced by BDNF or synaptic activity. In addition, MKL1 appears as a novel mediator of the signaling between ERK1/2 and SRF. Moreover, MKL1 is a likely regulator of SRF-driven transcription programs that underlie neuronal plasticity.
Interface Interactions Modulating Desensitization of the Kainate-Selective Ionotropic Glutamate Receptor Subunit GluR6
Authors: Zhang Yihong , Nayeem Naushaba , Nanao Max H. , Green Tim
Published: September 2006

Ionotropic glutamate receptors from the AMPA and kainate subfamilies share many functional and structural features, but it is unclear whether this similarity extends to the molecular mechanisms underlying receptor desensitization. The current model for desensitization in AMPA receptors involves the rearrangement of dimers formed between subunit agonist binding domains. Key evidence for this has come from a single point mutant (from leucine to tyrosine) that abolished desensitization and that was shown to stabilize the binding domain dimer. However, the desensitization of kainate receptors appears to differ from that of AMPA receptors in several key respects. Although the kinetics of AMPA receptor gating and desensitization are consistent with channels formed from two dimers, similar evidence for the functional involvement of dimers has not been found in kainate receptors. Furthermore, despite the homolog of the nondesensitizing tyrosine in AMPA subunits also being a tyrosine in wild-type kainate subunits, these receptors desensitize rapidly and completely. Using mutagenesis based on the crystal structure of the glutamate receptor subunit GluR6 S1S2 domain in complex with domoate, we identified four residues neighboring this tyrosine that differ between AMPA and kainate subunits and that contribute to the different desensitization kinetics of these receptors. Detailed analysis of the effects of mutations at these sites confirms that there is in fact a common general mechanism for desensitization in non-NMDA receptors, dependent on the stability of the binding domain dimer interface, and reveals the existence of potential agonist-specific desensitization pathways.
Oculomotor Instabilities in Zebrafish Mutantbelladonna: A Behavioral Model for Congenital Nystagmus Caused by Axonal Misrouting
Authors: Huang Ying-Yu , Rinner Oliver , Hedinger Patrik , Liu Shih-Chii , Neuhauss Stephan C. F.
Published: September 2006

A large fraction of homozygous zebrafish mutantbelladonna(bel) larvae display a reversed optokinetic response (OKR) that correlates with failure of the retinal ganglion cells to cross the midline and form the optic chiasm. Some of these achiasmatic mutants display strong spontaneous eye oscillations (SOs) in the absence of motion in the surround. The presentation of a stationary grating was necessary and sufficient to evoke SO. Both OKR reversal and SO depend on vision and are contrast sensitive.

We built a quantitative model derived frombel fwd(forward) eye behaviors. To mimic the achiasmatic condition, we reversed the sign of the retinal slip velocity in the model, thereby successfully reproducing both reversed OKR and SO. On the basis of the OKR data, and with the support of the quantitative model, we hypothesize that the reversed OKR and the SO can be completely attributed to RGC misrouting. The strong resemblance between the SO and congenital nystagmus (CN) seen in humans with defective retinotectal projections implies that CN, of so far unknown etiology, may be directly caused by a projection defect.
RTP801 Is Elevated in Parkinson Brain Substantia Nigral Neurons and Mediates Death in Cellular Models of Parkinson's Disease by a Mechanism Involving Mammalian Target of Rapamycin Inactivation
Authors: Malagelada Cristina , Ryu Elizabeth J. , Biswas Subhas C. , Jackson-Lewis Vernice , Greene Lloyd A.
Published: September 2006

The molecules underlying neuron loss in Parkinson's disease (PD) are essentially unknown, and current therapies focus on diminishing symptoms rather than preventing neuron death. We identified RTP801 as a gene whose transcripts were highly induced in a cellular model of PD in which death of neuronal catecholaminergic PC12 cells was triggered by the PD mimetic 6-OHDA. Here, we find that RTP801 protein is also induced in this and additional cellular and animal PD models. To assess the relevance of these observations to PD, we used immunohistochemistry to compare RTP801 expression in postmortem brains from PD and control patients. For all PD brains examined, expression was highly elevated within neuromelanin-containing neurons of the substantia nigra but not in cerebellar neurons. Evaluation of the potential role of RTP801 induction in our cellular model revealed that RTP801 overexpression is sufficient to promote death but does not further elevate death caused by 6-OHDA. Furthermore, RTP801 induction is requisite for death in our cellular PD models and in 6-OHDA-treated cultured sympathetic neurons in that its knockdown by short hairpin RNAs (shRNAs) is protective. The mechanism by which 6-OHDA and RTP801 induce neuron death appears to involve repression of mammalian target of rapamycin (mTOR) kinase activity, and such death is inhibited by shRNAs targeting TSC2 (tuberous sclerosis complex), a protein with which RTP801 interacts to block mTOR activation. Our findings thus suggest that the elevation of RTP801 we detect in PD substantia nigral neurons may mediate their degeneration and death and that RTP801 and its signaling cascade may be novel potential therapeutic targets for the disease.
The Effects of Clozapine on Cognitive Function and Regional Cerebral Blood Flow in the Negative Symptom Profile Schizophrenia
Authors: Zhao Jingping , He Xiaolin , Liu Zhening , Yang Desen
Published: September 2006

Objective:

Cognitive function and regional cerebral blood flow (rCBF) were studied in negative symptom profile schizophrenic patients by using WCST and SPECT.

Methods:

Twenty-one schizophrenic patients who matched the criteria of Andreason's negative symptom profile received SPECT and WCST, and then were treated with clozapine for 8 consecutive weeks. There were 28 and 12 normal subjects as the control groups of WCST and SPECT, respectively.

Results:

Compared with controls, significantly poorer performance on total trials of category (TT), persevering errors (PE), and non-persevering errors (NPE) of WCST were found in schizophrenia ( p < 0.05). The total score of the scale for assessment negative symptoms (SANS) was significantly related with poor TT ( r = 0.45, p < 0.01) and PE performance ( r = 0.45, p < 0.01). The poor TT, PE, and NPE tasks of WCST and SANS scores in the negative schizophrenic patients were significantly improved through clozapine treatment ( p < 0.05). The schizophrenic patients had a significantly lower rCBF in bilateral frontal and temporal lobes and lower change rate of rCBF in bilateral frontal lobes during WCST compared to normal controls ( p < 0.05).

Conclusions:

Negative symptom profile schizophrenia has cognitive deficits and lower rCBF in bilateral frontal and temporal lobes, which suggests that negative symptom profile schizophrenic patients have hypofrontality. Clozapine can improve negative symptoms and improve cognitive dysfunction, although it cannot improve reduced rCBF in the frontal lobes.
The Relationship between Barrier Courses and Persistence in Engineering
Authors: Suresh Radhika
Published: September 2006

Attrition in engineering programs continues to be an important issue for universities across the country. This study examined the connection between student performance in barrier courses and persistence in engineering. Quantitative results showed that high school academic experience, student behaviors (including study habits, work habits, coping strategies), students' perceptions about faculty behavior (including teaching styles and the “weed-out” culture), the perceived culture of support in the engineering school, and motivation to succeed in engineering all impact students' performance in barrier courses. Qualitative results showed that motivation to succeed might be the reason why some students persist even when they “struggle” with barrier courses.
Chronic Medical Conditions and Wishes to Die among Older Primary Care Patients
Authors: Kim Yeowon A. , Bogner Hillary R. , Brown Gregory K. , Gallo Joseph J.
Published: September 2006

Objective:

To determine the prevalence of wishes to die and the medical correlates of wishes to die among primary care patients aged 65 years and older.

Method:

Three-hundred and fifty-five adults with and without significant depressive symptoms who were screened in primary care offices and invited to participate completed a baseline in-home assessment. Participants were interviewed using standardized measures of medical conditions, functional status, and psychological status. Thoughts of death and wishes to die were assessed with standard questions from the Composite International Diagnostic Interview (CIDI) Depression Section.

Results:

The weighted point prevalence of thoughts of death was 9.7% and 6.1% for the wish to die. Several medical conditions were associated with a wish to die, for example myocardial infarction (MI). In multivariate models that adjusted for potentially influential characteristics, the association between a history of MI and the wish to die remained statistically significant (odds ratio (OR) = 3.32, 95% confidence interval (CI) (1.26, 8.75).

Conclusions:

Thoughts of death and a wish to die are common in older primary care patients and were more likely among persons with chronic medical conditions. Persons with a history of myocardial infarction may be particularly vulnerable to a wish to die.
Academic, Motivational, and Emotional Problems Identified by College Students in Academic Jeopardy
Authors: Isaak Matthew I. , Graves Kristy M. , Mayers Bethlyn O.
Published: September 2006

This study explored the difficulties that probationary students viewed as obstacles to their academic progress. These difficulties were compared to those identified by regularly matriculated students and to probationary students' deficits on a standardized study skills test. We compared the responses of participants ( N = 150) in an intervention program for probationary students on a 30-item checklist of academic difficulties to: a) the responses of regularly matriculated students ( N = 153); and b) probationary students' performance on the Survey of Study Habits and Attitudes (SSHA; Brown & Holtzman, 1967). Probationary students identified more motivational and stress-related checklist problems than did regularly matriculated students. Probationary students identified the same number of study skills problems as regularly matriculated students, despite scoring well below the 50th percentile on the SSHA's work methods scale. Implications for the design of interventions for probationary students are discussed, as are directions for future research.
Suicide Notes: Psychological and Clinical Profile
Authors: Bhatia Manjeet S. , Verma Satish K. , Murty O. P.
Published: September 2006

Objective:

Suicide is one of the leading causes of mortality in developing as well as developed countries. Psychological autopsy is supplementary to medical autopsy in finding out the correct cause of death. Suicide notes form an important component of psychological autopsy.

Method:

In the present study, psychosocial and clinical profile of 40 suicide note writers is present. The contents of suicide notes were also analysed.

Results:

A majority of suicide note writers were to 21 to 30 years of age (55%) and were males (65%). Home was the most common place for committing suicide (80%) and hanging was the most common method. All suicide notes were handwritten and a last wish was mentioned in 30%. Suicide note was most commonly addressed to a sibling (20%). Disturbed love affair and financial problems were the common reasons mentioned in suicide notes. Hopelessness and depression was the most common diagnosis in 52.5% cases.

Conclusion:

More studies are warranted to detect and analyze the suicide notes so that they not only help in confirming cause of death as suicide but also help in suicide prevention programs.
The Seek Mentoring Program: An Application of the Goal-Setting Theory
Authors: Sorrentino Diane M.
Published: September 2006

This article describes a pilot academic mentoring program carried out over 1 semester in the SEEK Program at the College of Staten Island, CUNY. The program was utilized to provide a resource for students whose overall grade point average was below 2.5, placing them at risk for academic dismissal. A goal-setting approach was used to aid the students in identifying and overcoming the obstacles to their academic success, in an effort to enhance the students' retention. Sixty-three students participated in 1 of 3 groups; the 3 groups consisted of a mentoring program combined with tutoring, a tutoring-only group, and a control group. Data collected in both the qualitative and quantitative formats supported the effectiveness of the SEEK Mentor Program. The program motivated the students to action, thus increasing the students' grade point average and retention rates.
Predictors of Graduation of Readmitted “At Risk” College Students
Authors: Berkovitz Roslyn A. , O'Quin Karen
Published: September 2006

We conducted an archival study of at-risk students who had “stopped out” of college for many reasons (academic dismissal, financial problems, personal problems, etc.) and who later were accepted to return to school. Approximately 27% of the accepted students chose not to return. Those who returned had higher grade point averages, had completed more semesters and more credits before stop-out, and had transferred in more credits than non-returners. Of the final sample of 290 students who returned, approximately 47% eventually graduated, a number that compares favorably to national graduation statistics. Sixteen variables were examined to predict whether the students later graduated or did not. In a hierarchical logistic regression, the only significant demographic variable was year of birth, with younger students being more likely to graduate. Two “intervention” variables were significant: students who had been academically dismissed were less likely to graduate, and those who participated in a pre-freshman summer orientation program were more likely to graduate. GPA upon readmission was not a significant predictor after controlling for other variables, although credits earned and semesters completed upon readmission were significantly positively related to graduation.
Does Proximity to Clinic Affect Immunization Rates and Blood Pressure?
Authors: Baumgardner Dennis J. , Halsmer Sarah E. , Steber Dale L. , Shah Dharmen S. , Mundt Marlon P.
Published: September 2006

Objective:

Primary care clinics are frequently placed in neighborhoods to improve access. Little is known whether or not this improves outcomes. We sought to determine if childhood immunization rates and adult blood pressure (BP) levels are related to proximity of home to clinic.

Method:

We conducted a retrospective chart review in a community family medicine clinic in a neighborhood grocery store (CC) and a hospital-based family medicine residency clinic (HC) in Milwaukee, Wisconsin. Randomly selected subjects included children aged 2–5 years ( n = 151 CC; 241 HC) and adult continuity patients ( n = 197 CC; 242 HC). ARC-GIS was used to geocode patient home addresses, and distances were analyzed using Kruskal-Wallis, Spearman's rank correlation, or Mann-Whitney test. Proportion of primary immunization by age 2 and age at completion, numerical BP, and proportion abnormal BP were each correlated to distance and driving distance to clinic.

Results:

Median driving distance of patient to clinic was significantly less for CC than HC (children = 1.47 versus 2.35 miles, p < 0.0001; adults = 1.53 versus 3.12, p < 0.001). For each clinic, and for all subjects combined, and for subsets by gender, ethnicity and insurance status, there was no significant correlation between proportion immunized by age 2 or age at completion and linear or categorical driving distance (or linear distance) to clinic ( p = 0.12–0.99), or between BP values or proportion abnormal and distances to clinic ( p = 0.44–0.97).

Conclusions:

In this urban area, proximity of home to clinic did not correlate with primary immunization completion or blood pressure in either a hospital-based or a community clinic.
A Sociodemographic, Phenomenological, and Long-Term Follow-up Study of Patients with Body Dysmorphic Disorder in Brazil
Authors: Fontenelle Leonardo F. , Telles Leonardo L. , Nazar Bruno P. , de Menezes Gabriela Bezerra , do Nascimento Antonio Leandro , Mendlowicz Mauro V. , Versiani Marcio
Published: September 2006

Objective:

The main characteristic of body dysmorphic disorder (BDD) is a preoccupation with an imagined defect in appearance in a normal-appearing person or an excessive preoccupation with appearance in a person with a small physical defect. In this non-controlled study, our objective was to describe the socio-demographic, phenomenological, and long-term outcome features of a Brazilian sample of patients with BDD.

Methods:

We performed a chart-review of the 166 patients who attended the Obsessions, Compulsions, and Impulsions Subprogram of the Institute of Psychiatry of the Federal University of Rio de Janeiro, Brazil, during the period between 1998 and 2005.

Results:

Twenty patients (12%) had clinically significant BDD. This sample was characterized by a predominance of female ( n = 11; 55%), single or divorced ( n = 18; 90%), and economically unproductive patients ( n = 17; 85%). We found an average of 2.5 current imagined defects per patient. The most frequently reported body parts of excessive concern were the overall appearance, size or shape of the face ( n = 7; 35%), the skin ( n = 6; 30%), the hair ( n = 6; 30%), the nose ( n = 5; 25%), and the body build and weight ( n = 5; 25%). Most individuals exhibited a chronic condition ( n = 13; 65%) and kept the same concerns during the course of the disorder ( n = 12; 60%). All patients displayed compulsive behaviors, including recurrent mirror checking ( n = 14; 70%), camouflaging ( n = 13; 65%), reassurance seeking by means of repetitive questioning of others ( n = 9; 45%), and excessive use of cosmetics ( n = 7; 35%). Two patients reported “do-it-yourself surgeries. Seven patients had current suicidal ideation (35%). Six patients (30%) showed no insight over their dysmorphic beliefs. Fifteen patients (95%) exhibited psychiatric comorbidities, mostly obsessive-compulsive disorder (OCD) ( n = 14, 70%) and major depressive disorder ( n = 11; 55%). The majority of patients were treated naturalistically with serotonin reuptake inhibitors ( n = 15; 75%), either solo or in association with antipsychotics ( n = 10; 50%). Nevertheless, only 5 (25%) responded favorably to treatment during the long-term follow-up (CGI < 2).

Conclusions:

BDD is a severe disorder that is frequently associated with other psychiatric conditions and responds poorly to treatment in the naturalistic setting. No significant trans-cultural variations were identified in the comparison between Brazilian, North American, and European samples.
The Efficacy of Seminar Courses
Authors: Tsui Lisa , Gao Eleanor
Published: September 2006

This study explores the relationship between the seminar course model and critical thinking development among students through qualitative data collected from four strategically chosen case study institutions. Results of a cross-case analysis suggest that the seminar approach provides fertile ground for the cultivation of critical thinking skills because it is conducive to the pursuit of active learning instructional methods. Differences in institutional context help illuminate how the seminar model is heavily and effectively used as a curricular vehicle at some schools, and why it is less prevalent at others. The efficacious relationship between seminar courses, active learning, and critical thinking development yields important implications for the link between curricular offerings and student retention.
Spending on Targeted Therapies for Duchenne Muscular Dystrophy
Authors: Bendicksen Liam , Kesselheim Aaron S. , Rome Benjamin N.
Published: March 2024

This study estimates public and private spending on genetically targeted treatments for Duchenne muscular dystrophy during years in which the drugs were marketed without completed confirmatory studies.
Titanium Nitride Microelectrode: A New Candidate for In Situ Electrochemical Transmission Electron Microscopy Study
Authors: Park Junbeom , Cheng Ningyan , Ge Binghui , Jodat Eva , Karl André , Pivak Yevheniy , Sun Hongyu , Garza Héctor Hugo Pérez , Basak Shibabrata , Eichel Rüdiger‐A.
Published: March 2024

In situ transmission electron microscopy (TEM) is increasingly utilized by researchers to explore various electrochemical applications in the quest to address climate change, aiming to comprehend underlying mechanisms and enhance performance. However, the conventional Pt microelectrode commonly used in in situ TEM poses limitations due to its low electron transparency and high catalytic activity. In this study, titanium nitride (TiNx) is introduced as a novel microelectrode material that can be fabricated following typical cleanroom processes. Through in situ Zn and Cu electrodeposition studies, it is shown how the low catalytic activity and higher electron transparency of TiNx enable obtaining stable electrochemical cycling and quantify the deposition on top of microelectrode in TEM mode, highlighting the benefit of TiNx microelectrodes for different in situ TEM studies.
iWood: An Intelligent Iontronic Device for Human‐Wood Interactions
Authors: Li Bin , Ge Ruiqing , Du Wenwen , Wang Zhenning , Peng Tao , Wang Ruojiang , Chang Yu , Pan Tingrui
Published: March 2024

Woodwork is involved in a variety of interactions with humans through physical contact, which may reveal valuable information if the tactile data can be unnoticeably extracted. In this work, an intelligent iontronic wood (iWood) device, along with its seamlessly integrated architecture into the woodwork, enabled by the iontronic sensing principle, is implemented. Notably, the tactile sensing structure is generated at the iontronic interface between ionic and conductive woods. In particular, the ionic wood is established by infusing an ionic liquid into the wood, followed by immobilizing it via chemical bonding, presenting both prominent ionic conductivity and excellent stability under pressure. By formatting the woods into identical strips, the high‐density tactile sensing array can be simply formed by a braiding process for a scalable interwoven structure. As a result, the iWood device has offered a high sensitivity over a broad detection of 0.5 MPa and an array of 40 × 90 units covering an area up to 3600 cm2. The iWood device is showcased as an interactive human interface, demonstrating its potential as a smart desktop capable of gesture and object recognition, a health‐tracking chair for real‐time ballistocardiograph monitoring, and an embedded intelligent floor for weight management and gait analysis.
Toward Sustainability in All‐Printed Accumulation Mode Organic Electrochemical Transistors
Authors: Makhinia Anatolii , Bynens Lize , Goossens Arwin , Deckers Jasper , Lutsen Laurence , Vandewal Koen , Maes Wouter , Beni Valerio , Andersson Ersman Peter
Published: March 2024

This study reports on the first all‐printed vertically stacked organic electrochemical transistors (OECTs) operating in accumulation mode; the devices, relying on poly([4,4′‐bis(2‐(2‐(2‐methoxyethoxy)ethoxy)ethoxy)‐2,2′‐bithiophen‐5,5′‐diyl]‐alt‐[thieno[3,2‐b]thiophene‐2,5‐diyl]) (pgBTTT) as the active channel material, are fabricated via a combination of screen and inkjet printing technologies. The resulting OECTs (W/L ≈5) demonstrate good switching performance; gm, norm ≈13 mS cm−1, µC* ≈21 F cm−1 V−1 s−1, ON–OFF ratio > 104 and good cycling stability upon continuous operation for 2 h. The inkjet printing process of pgBTTT is established by first solubilizing the polymer in dihydrolevoglucosenone (Cyrene), a non‐toxic, cellulose‐derived, and biodegradable solvent. The resulting ink formulations exhibit good jettability, thereby providing reproducible and stable p‐type accumulation mode all‐printed OECTs with high performance. Besides the environmental and safety benefits of this solvent, this study also demonstrates the assessment of how the solvent affects the performance of spin‐coated OECTs, which justifies the choice of Cyrene as an alternative to commonly used harmful solvents such as chloroform, also from a device perspective. Hence, this approach shows a new possibility of obtaining more sustainable printed electronic devices, which will eventually result in all‐printed OECT‐based logic circuits operating in complementary mode.