5,582 research outputs found

    Efficacy of needle-placement technique in radiofrequency ablation for treatment of lumbar facet arthropathy.

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    BACKGROUND:Many studies have assessed the efficacy of radiofrequency ablation to denervate the facet joint as an interventional means of treating axial low-back pain. In these studies, varying procedural techniques were utilized to ablate the nerves that innervate the facet joints. To date, no comparison studies have been performed to suggest superiority of one technique or even compare the prevalence of side effects and complications. MATERIALS AND METHODS:A retrospective chart review was performed on patients who underwent a lumbar facet denervation procedure. Each patient's chart was analyzed for treatment technique (early versus advanced Australian), preprocedural visual numeric scale (VNS) score, postprocedural VNS score, duration of pain relief, and complications. RESULTS:Pre- and postprocedural VNS scores and change in VNS score between the two groups showed no significant differences. Patient-reported benefit and duration of relief was greater in the advanced Australian technique group (P=0.012 and 0.022, respectively). The advanced Australian technique group demonstrated a significantly greater median duration of relief (4 months versus 1.5 months, P=0.022). Male sex and no pain-medication use at baseline were associated with decreased postablation VNS scores, while increasing age and higher preablation VNS scores were associated with increased postablation VNS scores. Despite increasing age being associated with increased postablation VNS scores, age and the advanced Australian technique were found to confer greater patient self-reported treatment benefit. CONCLUSION:The advanced Australian technique provides a significant benefit over the early Australian technique for the treatment of lumbar facet pain, both in magnitude and duration of pain relief

    Fermions in 3D Optical Lattices: Cooling Protocol to Obtain Antiferromagnetism

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    A major challenge in realizing antiferromagnetic (AF) and superfluid phases in optical lattices is the ability to cool fermions. We determine the equation of state for the 3D repulsive Fermi-Hubbard model as a function of the chemical potential, temperature and repulsion using unbiased determinantal quantum Monte Carlo methods, and we then use the local density approximation to model a harmonic trap. We show that increasing repulsion leads to cooling, but only in a trap, due to the redistribution of entropy from the center to the metallic wings. Thus, even when the average entropy per particle is larger than that required for antiferromagnetism in the homogeneous system, the trap enables the formation of an AF Mott phase.Comment: 4 pages; 5 figures; also see supplementary material in 2 pages with 1 figur

    A Fourier transform spectrometer for the measurement of atmospheric thermal radiation

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    Fourier transform spectrometer for measurement of atmospheric thermal radiatio

    Vlasov Description Of Dense Quark Matter

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    We discuss properties of quark matter at finite baryon densities and zero temperature in a Vlasov approach. We use a screened interquark Richardson's potential consistent with the indications of Lattice QCD calculations. We analyze the choices of the quark masses and the parameters entering the potential which reproduce the binding energy (B.E.) of infinite nuclear matter. There is a transition from nuclear to quark matter at densities 5 times above normal nuclear matter density. The transition could be revealed from the determination of the position of the shifted meson masses in dense baryonic matter. A scaling form of the meson masses in dense matter is given.Comment: 15 pages 4 figure

    Measurement of ozone transmissivity at low temperatures

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    Low temperature medium resolution measurements of the transmissivity of the ozone band have been made in the laboratory. The range of conditions under which the measurements were made are: -48 to -22 C, .0029 U .71 atmo.cm., 680 P 742 mmHg. The apparatus used is described briefly, measurement conditions are summarized and the resulting spectra are shown

    Drymus brunneus (Sahlberg) (Hemiptera: Rhyparochromidae): a seed bug introduced into North America

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    The occurrence of the adventive Drymus brunneus (Sahlberg) in North America is documented, and characteristics to distinguish this Old World species from D. unus (Say) are described and illustrated. A revised key to the Western Hemisphere species of Drymus is included

    Coulomb blockade and quantum tunnelling in the low-conductivity phase of granular metals

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    We study the effects of Coulomb interaction and inter-grain quantum tunnelling in an array of metallic grains using the phase-functional approach for temperatures TT well below the charging energy EcE_{c} of individual grains yet large compared to the level spacing in the grains. When the inter-grain tunnelling conductance g1g\gg1, the conductivity σ\sigma in dd dimensions decreases logarithmically with temperature (σ/σ0112πgdln(gEc/T)\sigma/\sigma_{0}\sim1-\frac{1}{2\pi gd}\ln(gE_{c}/T)), while for g0g\to0, the conductivity shows simple activated behaviour (σexp(Ec/T)\sigma \sim \exp(-E_c/T)). We show, for bare tunnelling conductance g1g \gtrsim 1, that the parameter γg(12/(gπ)ln(gEc/T))\gamma \equiv g(1-2/(g\pi)\ln(gE_{c}/T)) determines the competition between charging and tunnelling effects. At low enough temperatures in the regime 1γ1/βEc1\gtrsim \gamma \gg 1/\sqrt{\beta E_{c}}, a charge is shared among a finite number N=(Ec/T)/ln(π/2γz)N=\sqrt{(E_{c}/T)/\ln(\pi/2\gamma z)} of grains, and we find a soft activation behaviour of the conductivity, σz1exp(2(Ec/T)ln(π/2γz))\sigma\sim z^{-1}\exp(-2\sqrt{(E_{c}/T)\ln(\pi/2\gamma z)}), where zz is the effective coordination number of a grain.Comment: 11 pages REVTeX, 3 Figures. Appendix added, replaced with published versio

    Intranasal immunisation with Ag85B peptide 25 displayed on Lactococcus lactis using the PilVax platform induces antigen-specific B- and T-cell responses.

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    Mycobacterium tuberculosis (Mtb) remains a global epidemic despite the widespread use of BCG. Consequently, novel vaccines are required to facilitate a reduction in Mtb morbidity and mortality. PilVax is a peptide delivery strategy for the generation of highly specific mucosal immune responses and is based on the food-grade bacterium Lactococcus lactis that is used to express selected peptides engineered within the Streptococcus pyogenes M1T1 pilus, allowing for peptide amplification, stabilisation, and enhanced immunogenicity. In the present study, the dominant T cell epitope from the Mtb protein Ag85B was genetically engineered into the pilus backbone subunit and expressed on the surface of L. lactis. Western blot and flow cytometry confirmed formation of pilus containing the peptide DNA sequence. B cell responses in intranasally vaccinated mice were analysed by ELISA while T cell responses were analysed by flow cytometry. Serum titres of peptide specific IgG and IgA were detected, confirming vaccination produced antibodies against the cognate peptide. Peptide-specific IgA was also detected across several mucosal sites sampled. Peptide-specific CD4+ T cells were detected at levels similar to those of mice immunised with BCG. PilVax immunisation resulted in an unexpected increase in the numbers of CD3+ CD4- CD8- (double negative, DN) T cells in the lungs of vaccinated mice. Analysis of cytokine production following stimulation with the cognate peptide showed the major cytokine producing cells to be CD4+ T cells and DN T cells. This study provides insight into the antibody and peptide specific cellular immune responses generated by PilVax vaccination and demonstrates the suitability of this vaccine for conducting a protection study

    Simulating `Complex' Problems with Quantum Monte Carlo

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    We present a new quantum Monte Carlo algorithm suitable for generically complex problems, such as systems coupled to external magnetic fields or anyons in two spatial dimensions. We find that the choice of gauge plays a nontrivial role, and can be used to reduce statistical noise in the simulation. Furthermore, it is found that noise can be greatly reduced by approximate cancellations between the phases of the (gauge dependent) statistical flux and the external magnetic flux.Comment: Revtex, 11 pages. 3 postscript files for figures attache
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