718 research outputs found
Dying Dyons Don't Count
The dyonic 1/4-BPS states in 4D string theory with N=4 spacetime
supersymmetry are counted by a Siegel modular form. The pole structure of the
modular form leads to a contour dependence in the counting formula obscuring
its duality invariance. We exhibit the relation between this ambiguity and the
(dis-)appearance of bound states of 1/2-BPS configurations. Using this insight
we propose a precise moduli-dependent contour prescription for the counting
formula. We then show that the degeneracies are duality-invariant and are
correctly adjusted at the walls of marginal stability to account for the
(dis-)appearance of the two-centered bound states. Especially, for large black
holes none of these bound states exists at the attractor point and none of
these ambiguous poles contributes to the counting formula. Using this fact we
also propose a second, moduli-independent contour which counts the "immortal
dyons" that are stable everywhere.Comment: 27 pages, 2 figures; one minus sign correcte
Glutathione-Induced Release of Zeatin From Functionalized Gold Nanovectors
The paper shows our preliminary results on the different spectroscopic behavior of three types of gold nanoparticles (obtained respectively by chemical synthesis, laser ablation in pure water and laser ablation in a citrate solution) modified with trans-zeatin, a plant growth regulator, in presence of glutathione. The reaction of ligand substitution of the adsorbed zeatin with glutathione is studied through surface enhanced Raman spectroscopy and is revealed to occur only when citrate-laser ablated gold nanoparticles are employed, making these particles potentially good candidates as vehicles of zeatin inside plant cells for future agricultural applications
Thermodynamics of Dipolar Chain Systems
The thermodynamics of a quantum system of layers containing perpendicularly
oriented dipolar molecules is studied within an oscillator approximation for
both bosonic and fermionic species. The system is assumed to be built from
chains with one molecule in each layer. We consider the effects of the
intralayer repulsion and quantum statistical requirements in systems with more
than one chain. Specifically, we consider the case of two chains and solve the
problem analytically within the harmonic Hamiltonian approach which is accurate
for large dipole moments. The case of three chains is calculated numerically.
Our findings indicate that thermodynamic observables, such as the heat
capacity, can be used to probe the signatures of the intralayer interaction
between chains. This should be relevant for near future experiments on polar
molecules with strong dipole moments.Comment: 15 pages, 5 figures, final versio
Bound Chains of Tilted Dipoles in Layered Systems
Ultracold polar molecules in multilayered systems have been experimentally
realized very recently. While experiments study these systems almost
exclusively through their chemical reactivity, the outlook for creating and
manipulating exotic few- and many-body physics in dipolar systems is
fascinating. Here we concentrate on few-body states in a multilayered setup. We
exploit the geometry of the interlayer potential to calculate the two- and
three-body chains with one molecule in each layer. The focus is on dipoles that
are aligned at some angle with respect to the layer planes by means of an
external eletric field. The binding energy and the spatial structure of the
bound states are studied in several different ways using analytical approaches.
The results are compared to stochastic variational calculations and very good
agreement is found. We conclude that approximations based on harmonic
oscillator potentials are accurate even for tilted dipoles when the geometry of
the potential landscape is taken into account.Comment: 10 pages, 6 figures. Submitted to Few-body Systems special issue on
Critical Stability, revised versio
A nationwide overview of 1-year mortality in cardiac arrest patients admitted to intensive care units in the Netherlands between 2010 and 2016
Aim: Worldwide, cardiac arrest (CA) remains a major cause of death. Most post-CA patients are admitted to the intensive care unit (ICU). The aim of this study is to describe mortality rates and possible changes in mortality rates in patients with CA admitted to the ICU in the Netherlands between 2010 and 2016. Methods: In this study, we included all adult CA patients registered in the National Intensive Care Evaluation (NICE) regist
Acesso Lateral De Keblish Melhora A Inclinação Da Patela Na Artroplastia Do Joelho Valgo
To compare the clinical and radiological outcomes of conventional medial and lateral approaches for total knee replacement in the valgus osteoarthritic knee. Methods In this randomized controlled trial, 21 patients with valgus knee osteoarthritis were randomized to total knee replacement through medial or lateral approach. The primary outcome was radiographic patellar tilt. Secondary outcomes were visual analogue scale of pain, postoperative levels of hemoglobin, and clinical aspect of the operative wound. Results There were no differences between the groups regarding other clinical variables. Mean lateral tilt of the patella was 3.1 degrees (SD ± 5.3) in the lateral approach group and 18 degrees (SD ± 10.2) in the medial approach group (p = 0.02). There were no differences regarding the secondary outcomes. Conclusion Lateral approach provided better patellar tilt following total knee replacement in valgus osteoarthritic knee. © 2016 Sociedade Brasileira de Ortopedia e Traumatologia51668068
Comparison Of Puddu Osteotomy With Or Without Autologous Bone Grafting: A Prospective Clinical Trial
To test the hypothesis that autologous iliac bone grafts do not enhance clinical results and do not decrease complication rates in patients submitted to medial opening-wedge high tibial osteotomy. Methods: Forty patients allocated in a randomized, two-armed, double-blinded clinical trial were evaluated between 2007 and 2010. The primary outcome was Knee Society Score. Radiographic measurement of the frontal anatomical femoral-tibial angle and the progression of osteoarthritis according to the modified Ahlback classification were used as secondary outcomes. Results: There was no difference in KSS scale between the graft group (64.4. ±. 21.8) and the graftless group (61.6. ±. 17.3; p = 0.309). There was no difference of angle between the femur and tibia in the frontal plane between the groups (graft = 184. ±. 4.6 degrees, graftless = 183.4. ±. 5.1 degrees; p = 1.0), indicating that there is no loss of correction due to the lack of the graft. There was significant worsening of osteoarthritis in a greater number of patients in the graft group (p = 0.005). Conclusion: Autologous iliac bone graft does not improve clinical outcomes in medium and long-term follow-up of medial opening-wedge high tibial osteotomy fixed with a first generation Puddu plate in the conditions of this study. © 2016 Sociedade Brasileira de Ortopedia e Traumatologia
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