Changes in ensemble activity of hippocampus CA1 neurons induced by chronic morphine administration in freely behaving mice

The hippocampus plays an important role in the formation of new memories and spatial navigation. Recently, growing evidence supports the view that it is also involved in addiction to opiates and other drugs. Theoretical and experimental studies suggest that hippocampal neural-network oscillations at specific frequencies and unit firing patterns reflect information of learning and memory encoding. Here, using multichannel recordings from the hippocampal CA1 area in behaving mice, we investigated the phase correlations between the theta (4-10 Hz) and gamma (40-100 Hz) oscillations, and the timing of spikes modulated by these oscillations. Local field potentials and single unit recordings in the CA1 area of mice receiving chronic morphine treatment revealed that the power of the theta rhythm was strongly increased; at the same time, the theta frequency during different behavioral states shifted markedly, and the characteristic coupling of theta and gamma oscillations was altered. Surprisingly, though the gamma oscillation frequency changed, the power of gamma lacking theta did not. Moreover, the timing of pyramidal cell spikes relative to the theta rhythm and the timing of interneuron spikes relative to the gamma rhythm changed during chronic morphine administration. Furthermore, these responses were impaired by a selective D1/D5 receptor antagonist intra-hippocampus injection. These results indicate that chronic morphine administration induced the changes of ensemble activity in the CA1 area, and these changes were dependent on local dopamine receptor activation.

Scalable templated growth of graphene nanoribbons on SiC

In spite of its excellent electronic properties, the use of graphene in field-effect transistors is not practical at room temperature without modification of its intrinsically semimetallic nature to introduce a bandgap. Quantum confinement effects can create a bandgap in graphene nanoribbons, but existing nanoribbon fabrication methods are slow and often produce disordered edges that compromise electronic properties. Here, we demonstrate the self-organized growth of graphene nanoribbons on a templated silicon carbide substrate prepared using scalable photolithography and microelectronics processing. Direct nanoribbon growth avoids the need for damaging post-processing. Raman spectroscopy, high-resolution transmission electron microscopy and electrostatic force microscopy confirm that nanoribbons as narrow as 40 nm can be grown at specified positions on the substrate. Our prototype graphene devices exhibit quantum confinement at low temperatures (4 K), and an on-off ratio of 10 and carrier mobilities up to 2,700 cm(2) V(-1) s(-1) at room temperature. We demonstrate the scalability of this approach by fabricating 10,000 top-gated graphene transistors on a 0.24-cm(2) SiC chip, which is the largest density of graphene devices reported to date.

Mn valence, magnetic, and electrical properties of LaMnO3+δ nanofibers by electrospinning

LaMnO3+δ nanofibers have been prepared by electrospinning. The nearly 70% of Mn atoms is Mn4+, which is much higher than that in the nanoparticles. The average grain size of our fibers is approximately 20 nm, which is the critical size producing the nanoscale effect. The nanofibers exhibit a very broad magnetic transition with Tc≈255 K, and the Tc onset is around 310 K. The blocking temperature TB is 180 K. The sample shows weak ferromagnetic property above the TB and below Tc and superparamagnetic property near the Tc onset. The resistivity measurements show a metal-insulator transition near 210 K and an upturn at about 45 K.

Search for new physics with a dijet plus missing E(T) signature in pp collisions at √s=1.96 TeV

We present results of a signature-based search for new physics using a dijet plus missing transverse energy (E(T)) data sample collected in 2  fb⁻¹ of pp collisions at √s=1.96  TeV with the CDF II detector at the Fermilab Tevatron. We observe no significant event excess with respect to the standard model prediction and extract a 95% C.L. upper limit on the cross section times acceptance for a potential contribution from a nonstandard model process. The search is made by using novel, data-driven techniques for estimating backgrounds that are applicable to first searches at the LHC.

Molecular characteristics and expression profiles of glycerol-3-phosphate dehydrogenase 1 (GPD1) gene in pig

The cytosolic activity of glycerol-3-phosphate dehydrogenase 1 (GPD1, EC 1.1.1.8) plays an important role in the synthesis of triacylglycerol and in the transport of reducing equivalents from the cytosol to mitochondria. Here we report the full-length genomic sequence of porcine GPD1 gene including promoter region. Porcine GPD1 gene contains eight exons and seven introns. Using the ImpRH, the GPD1 gene was mapped on chromosome 5. Sub-cellular localization of the pig GPD1 was localized in cytoplasm by GFP reporter gene. The full-length CDS of porcine GPD1 gene comprises 1050 nucleotides and it encodes 349 amino acids. Using the CDS sequences of 17 species, we built the phylogeny tree of GPD1 gene. We investigated the expression level of the gene in 13 different tissues and time course from birth to postnatal day 28 in longissinus doris muscle (LD) and in cerebrum. The result shows that porcine GPD1 gene is expressed in almost all tissues we tested but its levels of expression varies widely over 2 orders of magnitude. LD and the cerebrum have similar expression pattern that is at a low level at birth and increasing with aging to the highest level at postnatal day 8 in LD and postnatal day 14 in cerebrum. But weaning decreased the expression level of the GPD1 gene. This may partially explains the effects of weaning on energy metabolism.

Abnormal DNA methylation in peripheral blood mononuclear cells from patients with vitiligo

BACKGROUND

Vitiligo is a skin disorder characterized by the destruction of melanocytes by autoreactive lymphocytes. The genetic and environmental factors that trigger the autoimmune response are poorly understood. However, alterations to epigenetic DNA methylation patterns contribute to many other autoimmune diseases.

OBJECTIVES

To investigate genomic and gene-specific DNA methylation levels in peripheral blood mononuclear cells (PBMCs) of patients with vitiligo and to relate any changes to the expression of genes that regulate methylation, as well as the autoimmune-related gene IL10.

METHODS

We quantified global methylcytosine levels in PBMCs from 20 patients with vitiligo and 20 healthy controls. mRNA levels of DNA methyltransferases (DNMTs), methyl-DNA binding domain proteins (MBDs) and interleukin (IL)-10 were measured by real-time reverse transcriptase-polymerase chain reaction. Methylation of an IL10 regulatory element domain was determined by bisulphite genomic sequencing.

RESULTS

Genomic DNA methylation in PBMCs of patients with vitiligo was increased relative to healthy controls (P = 0·012). DNMT1, MBD1, MBD3, MBD4 and MeCP2 expression was significantly higher than in control PBMCs (P = 0·013, 0·001, 0·005, 0·001 and 0·001, respectively). MBD1 and MBD3 expression correlated positively with global DNA methylation in vitiligo PBMCs (MBD1: r = 0·519, P = 0·019; MBD3: r = 0·529, P = 0·016). IL10 expression was significantly decreased (P = 0·030), and an IL-10 enhancer region was hypermethylated in vitiligo PBMCs compared with controls (P = 0·014).

CONCLUSIONS

These data show that levels of DNA methylation are altered in PBMCs of patients with vitiligo, and this may contribute to disease activity by affecting the expression of autoimmunity-related genes.

Exclusion of an exotic top quark with -4/3 electric charge using soft lepton tagging

We present a measurement of the electric charge of the top quark using pp collisions corresponding to an integrated luminosity of 2.7 fb(-1) at the CDF II detector. We reconstruct tt events in the lepton + jets final state. We use soft lepton taggers to determine the flavor of the b jets, which we use to reconstruct the top quark's electric charge and exclude an exotic top quark with -4/3 charge at 95% confidence level. This is the strongest exclusion of the exotic charge scenario and the first to use soft leptons for this purpose.

The relationship between CAG repeat length polymorphism and infertility in Southern Chinese Han women

OBJECTIVE

To research the relationship between polymorphism of trinucleotide (CAG)n repeat alleles of the Exon 1 of androgen receptor gene and women with polycystic ovary syndrome (PCOS), or with endometriosis.

MATERIALS AND METHODS

One hundred and forty-one control women and 74 women with PCOS and with endometriosis were recruited. The (CAG)n repeat alleles were genotyped with 3100 genetic analyser. The repeat number and frequency distributions of (CAG)n alleles were compared and analyzed statistically.

RESULTS

The results showed that mean repeat number of the (CAG)n was significantly lower in women with PCOS than in controls (p<0.001). The mean repeat number of the (CAG)n was significantly different between infertile women with endometriosis (p<0.05). However, the differences between infertile women with PCOS and fertile women with PCOS was not significant (p>0.05).

CONCLUSIONS

These data indicated that (CAG)n repeat polymorphism have some influence, but have not a straight relationship in infertile women with PCOS and with endometriosis in this research population.

Higher-order dispersion compensation to enable a 3.6 micros wavelength-maintaining delay of a 100 Gb/s DQPSK signal

We demonstrate a method for dispersion slope compensation of a conversion/dispersion-based optical delay to enable 100 Gb/s operation based on a spatial light modulator and fiber Bragg gratings. A continuous delay of up to 3.6 micros for 100, 80, and 20 Gb/s differential quadrature phase-shift-keyed (DQSPK) and 50, 40, and 10 Gb/s differential phase-shift-keyed (DPSK) waveforms is shown. A time-delay bit-rate product of approximately 360,000 for 100 Gb/s DQPSK with wavelength-maintaining operation is achieved.

Search for the production of scalar bottom quarks in pp collisions at square root(s) = 1.96 TeV

We report on a search for direct scalar bottom quark (sbottom) pair production in pp collisions at square root(s) = 1.96 TeV, in events with large missing transverse energy and two jets of hadrons in the final state, where at least one of the jets is required to be identified as originating from a b quark. The study uses a collider detector at Fermilab Run II data sample corresponding to 2.65 fb(-1) of integrated luminosity. The data are in agreement with the standard model. In an R-parity conserving minimal supersymmetric scenario, and assuming that the sbottom decays exclusively into a bottom quark and a neutralino, 95% confidence-level upper limits on the sbottom pair production cross section of 0.1 pb are obtained. For neutralino masses below 70 GeV/c2, sbottom masses up to 230 GeV/c2 are excluded at 95% confidence level.