An Improved CVDD Bur Used in Ultrasonic Dental System for Enamel Removal

AbstractThe aim of this paper is to increase enamel removal rate of dental diamond bur used in ultrasonic system so as to realize and promote its clinical applications. The cutting performances of the burs made by the electroplated diamond and by the chemical vapor deposition diamond (CVDD) are compared by experiment. It is found that the CVDD bur can achieve a higher removal rate. Detailed observation of the microphotograph of cut surface reveals that the superior performance of the CVDD bur is related to the morphology of the CVDD bur and the chips it produced. There are large amount of small cutting edges on the top of large size diamonds of the CVDD burs which results in tiny cutting chips. The materials along the plowed grooves left by the large size diamonds are removed by the adjacent small cutting edges. This action enables the cutting process to be carried out continuously rather than clogging the downward movement of the tool as experienced by the use of the electroplated diamond bur. But on the other hand, the too small chips also restrict the enamel removal rate. Hence a novel design of improved CVDD bur with fewer small cutting edges is proposed. The amount of cutting edges is reduced by heating the existing bur at 700°C for various time periods. It is found that the enamel removal rate along and perpendicular to enamel prism directions can be increased by 60% and 30%, respectively as compared with the untreated CVDD bur when it is heated in the nitrogen environment for 10minutes

Epitope recognition of peptide-imprinted polymers for Regenerating protein 1 (REG1)

Molecularly imprinted polymers (MIPs) were developed to replace natural antibodies with a cost-effective and durable synthetic material. Molecular imprinting of proteins conventionally utilizes the whole protein as the template, which is complex (as many different epitopes may be imprinted) and expensive. In this work, seven peptides (13–18 amino acids) were synthesized and used as templates for the imprinting and recognition of Regenerating Protein 1 (REG1). REG1 is involved in the proliferation and differentiation of diverse cell types, and was recently described as a urinary biomarker for pancreatic ductal adenocarcinoma (PDAC). Peptide-imprinted poly(ethylene-co-vinyl alcohol)s (PIPs), containing four different mole fractions of ethylene were cast on screen-printed electrodes to find the optimum composition for both the sensing and the extraction of REG1 in an E. coli culture medium. Peptides with fewer than 16 amino acids and two or three aromatic and hydrophobic groups have a higher affinity for MIPs of poly(ethylene-co-vinyl alcohol) (EVAL) with 27 mol% of ethylene, while those with four aromatic and hydrophobic groups have a higher affinity for MIPs with EVALs that contain 32 mol% of ethylene. The peptide / EVAL combination that maximized both imprinting effectiveness and response to REG1B was the sequence NEDRETWVDADLY imprinted into 32 mol% EVAL. This EVAL composition and template peptide were then modified by incorporation of magnetic nanoparticles, thus extending applications for PIPs to include extraction of REG1 protein from E. coli culture medium

Characterization, identification, and cloning of the S-layer protein from Cytophaga sp

We characterized, identified, and cloned a major protein which comprised 16% of the total proteins from Cytophaga sp. cell lysate. After French pressing, the fraction of cell envelope was treated with 0.2% Triton X-100 to remove cell membranes. Subsequent SDS-PAGE analysis of the Triton X-100-insoluble cell wall revealed a protein of 120 kDa with a pI of 5.4, which was identified by gold immunostaining as the surface (S)-layer protein of this soil bacterium. The nucleotide sequence of the cloned S-layer protein gene (slp) encoding this protein consisted of 3144 nucleotides with an ORF for 1047 amino acids, which included a typical 32-amino acid leader peptide sequence. Amino acid sequence alignment revealed 29-48% similarity between this protein and the S-layer proteins from other prokaryotic organisms. The 120-kDa protein from the Cytophaga sp. cell lysate has been characterized as a member of the S-layer proteins, and the slp gene was cloned and expressed in Escherichia coli. E. coli harboring the plasmid containing the 600- or 800-bp DNA fragment upstream of the initiation codon of the slp gene, in the presence of the reporter gene rsda (raw starch digesting amylase), showed amylase activity in starch containing plate. The putative promoter region of slp located 600 bp upstream of the initiation codon might be used for foreign gene expression

Magnetotransport in two-dimensional electron gas at large filling factors

We derive the quantum Boltzmann equation for the two-dimensional electron gas in a magnetic field such that the filling factor $\nu \gg 1$. This equation describes all of the effects of the external fields on the impurity collision integral including Shubnikov-de Haas oscillations, smooth part of the magnetoresistance, and non-linear transport. Furthemore, we obtain quantitative results for the effect of the external microwave radiation on the linear and non-linear $dc$ transport in the system. Our findings are relevant for the description of the oscillating resistivity discovered by Zudov {\em et al.}, zero-resistance state discovered by Mani {\em et al.} and Zudov {\em et al.}, and for the microscopic justification of the model of Andreev {\em et al.}. We also present semiclassical picture for the qualitative consideration of the effects of the applied field on the collision integral.Comment: 28 pages, 19 figures; The discussion of the role of the effect of the microwave field on the distribution function is revised (see also cond-mat/0310668). Accepted in Phys. Rev.

Immersive multi-user decision training games with ARLearn

Serious gaming approaches so far focus mainly on skill development, motivational aspects or providing immersive learning situations. Little work has been reported to foster awareness and decision competencies in complex deci-sion situations involving incomplete information and multiple stakeholders. We address this issue exploring the technical requirements and possibilities to de-sign games for such situations in three case studies: a hostage taking situation, a multi-stakeholder logistics case, and a health-care related emergency case. To implement the games, we use a multi-user enabled mobile game development platform (ARLearn). We describe the underlying real world situations and edu-cational challenges and analyse how these are reflected in the ARLearn games realized. Based on these cases we propose a way to increase the immersiveness of mobile learning games.SALOM

Nicotine-activated descending facilitation on spinal NMDA-dependent reflex potentiation from pontine tegmentum in rats

This study was conducted to investigate the possible neurotransmitter that activates the descending pathways coming from the dorsolateral pontine tegmentum (DPT) to modulate spinal pelvic-urethra reflex potentiation. External urethra sphincter electromyogram (EUSE) activity in response to test stimulation (TS, 1/30 Hz) and repetitive stimulation (RS, 1 Hz) on the pelvic afferent nerve of 63 anesthetized rats were recorded with or without microinjection of nicotinic cholinergic receptor (nAChR) agonists, ACh and nicotine, to the DPT. TS evoked a baseline reflex activity with a single action potential (1.00 +/- 0.00 spikes/stimulation, n = 40), whereas RS produced a long-lasting reflex potentiation (16.14 +/- 0.96 spikes/stimulation, n = 40) that was abolished by D-2-amino-5-phosphonovaleric acid (1.60 +/- 0.89 spikes/stimulation, n = 40) and was attenuated by 2,3-dihydroxy-6-nitro-7sulfamoyl-benzo (F) quinoxaline (7.10 +/- 0.84 spikes/stimulation, n = 40). ACh and nicotine microinjections to DPT both produced facilitation on the RS-induced reflex potentiation (23.57 +/- 2.23 and 28.29 +/- 2.36 spikes/stimulation, P = 0.01, n = 10 and 20, respectively). Pretreatment of selective nicotinic receptor antagonist, chlorisondamine, reversed the facilitation on RS-induced reflex potentiation caused by nicotine (19.41 +/- 1.21 spikes/stimulation, P = 0.01, n = 10) Intrathecal WAY-100635 and spinal transection at the T(1) level both abolished the facilitation on reflex potentiation resulting from the DPT nicotine injection (12.86 +/- 3.13 and 15.57 +/- 1.72 spikes/stimulation, P < 0.01, n = 10 each). Our findings suggest that activation of nAChR at DPT may modulate N-methyl-D-aspartic acid-dependent reflex potentiation via descending serotonergic neurotransmission. This descending modulation may have physiological/pathological relevance in the neural controls of urethral closure

Acute anal stretch inhibits NMDA-dependent pelvic-urethra reflex potentiation via spinal GABAergic inhibition in anesthetized rats

The impact of acute anal stretch on the pelvic-urethra reflex potentiation was examined in urethane-anesthetized rats by recording the external urethra sphincter electromyogram activity evoked by the pelvic afferent stimulation. Test stimulation (1 stimulation/30 s) evoked a baseline reflex activity with a single action potential that was abolished by gallamine (5 mg/kg iv). On the other hand, the repetitive stimulation (1 stimulation/1 s) induced spinal reflex potentiation (SRP) that was attenuated by intrathecal 6-cyano-7-nitroquinoxaline- 2,4-dione (a glutamatergic alpha-amino-3-hydroxy-5-methyl- 4-isoxazoleproprionat receptor antagonist, 100 mu M, 10 mu l) and D-2-amino-5-phosphonovalerate [a glutamatergic N-methyl-D-aspartate (NMDA) antagonist, 100 mu M, 10 mu l]. Acute anal stretch using a mosquito clamp with a distance of 4 mm exhibited no effect, whereas distances of 8 mm attenuated and 12 mm abolished the repetitive stimulation-induced SRP. Intrathecal NMDA (100 mu M, 10 mu l) reversed the abolition on SRP caused by anal stretch. On the other hand, pretreated bicuculline [gamma-aminobutyric acid (GABA) A receptor antagonist, 100 mu M, 10 mu l] but not hydroxysaclofen (GABA(B) receptor antagonist) counteracted the abolition on the repetitive stimulation-induced SRP caused by the anal stretch. All of the results suggested that anal stretch may be used as an adjunct to assist voiding dysfunction in patients with overactive urethra sphincter and that GABAergic neurotransmission is important in the neural mechanisms underlying external urethra sphincter activity inhibited by anal stretch

Measurements of the observed cross sections for e+e−→e^+e^-\to exclusive light hadrons containing π0π0\pi^0\pi^0 at s=3.773\sqrt s= 3.773, 3.650 and 3.6648 GeV

By analyzing the data sets of 17.3, 6.5 and 1.0 pb$^{-1}$ taken, respectively, at $\sqrt s= 3.773$, 3.650 and 3.6648 GeV with the BES-II detector at the BEPC collider, we measure the observed cross sections for $e^+e^-\to \pi^+\pi^-\pi^0\pi^0$, $K^+K^-\pi^0\pi^0$, $2(\pi^+\pi^-\pi^0)$, $K^+K^-\pi^+\pi^-\pi^0\pi^0$ and $3(\pi^+\pi^-)\pi^0\pi^0$ at the three energy points. Based on these cross sections we set the upper limits on the observed cross sections and the branching fractions for $\psi(3770)$ decay into these final states at 90% C.L..Comment: 7 pages, 2 figure

Partial wave analysis of J/\psi \to \gamma \phi \phi

Using $5.8 \times 10^7 J/\psi$ events collected in the BESII detector, the radiative decay $J/\psi \to \gamma \phi \phi \to \gamma K^+ K^- K^0_S K^0_L$ is studied. The $\phi\phi$ invariant mass distribution exhibits a near-threshold enhancement that peaks around 2.24 GeV/$c^{2}$. A partial wave analysis shows that the structure is dominated by a $0^{-+}$ state ($\eta(2225)$) with a mass of $2.24^{+0.03}_{-0.02}{}^{+0.03}_{-0.02}$ GeV/$c^{2}$ and a width of $0.19 \pm 0.03^{+0.06}_{-0.04}$ GeV/$c^{2}$. The product branching fraction is: $Br(J/\psi \to \gamma \eta(2225))\cdot Br(\eta(2225)\to \phi\phi) = (4.4 \pm 0.4 \pm 0.8)\times 10^{-4}$.Comment: 11 pages, 4 figures. corrected proof for journa

Direct Measurements of Absolute Branching Fractions for D0 and D+ Inclusive Semimuonic Decays

By analyzing about 33 $\rm pb^{-1}$ data sample collected at and around 3.773 GeV with the BES-II detector at the BEPC collider, we directly measure the branching fractions for the neutral and charged $D$ inclusive semimuonic decays to be $BF(D^0 \to \mu^+ X) =(6.8\pm 1.5\pm 0.7)$ and $BF(D^+ \to \mu^+ X) =(17.6 \pm 2.7 \pm 1.8)$, and determine the ratio of the two branching fractions to be $\frac{BF(D^+ \to \mu^+ X)}{BF(D^0 \to \mu^+ X)}=2.59\pm 0.70 \pm 0.25$