Optical Spin Initialization and Non-Destructive Measurement in a Quantum Dot Molecule

The spin of an electron in a self-assembled InAs/GaAs quantum dot molecule is optically prepared and measured through the trion triplet states. A longitudinal magnetic field is used to tune two of the trion states into resonance, forming a superposition state through asymmetric spin exchange. As a result, spin-flip Raman transitions can be used for optical spin initialization, while separate trion states enable cycling transitions for non-destructive measurement. With two-laser transmission spectroscopy we demonstrate both operations simultaneously, something not previously accomplished in a single quantum dot.Comment: Accepted for publication in Phys. Rev. Let

Magnetically-controlled velocity selection in a cold atom sample using stimulated Raman transitions

We observe velocity-selective two-photon resonances in a cold atom cloud in the presence of a magnetic field. We use these resonances to demonstrate a simple magnetometer with sub-mG resolution. The technique is particularly useful for zeroing the magnetic field and does not require any additional laser frequencies than are already used for standard magneto-optical traps. We verify the effects using Faraday rotation spectroscopy.Comment: 5 pages, 6 figure

Cold atom confinement in an all-optical dark ring trap

We demonstrate confinement of $^{85}$Rb atoms in a dark, toroidal optical trap. We use a spatial light modulator to convert a single blue-detuned Gaussian laser beam to a superposition of Laguerre-Gaussian modes that forms a ring-shaped intensity null bounded harmonically in all directions. We measure a 1/e spin-relaxation lifetime of ~1.5 seconds for a trap detuning of 4.0 nm. For smaller detunings, a time-dependent relaxation rate is observed. We use these relaxation rate measurements and imaging diagnostics to optimize trap alignment in a programmable manner with the modulator. The results are compared with numerical simulations.Comment: 5 pages, 4 figure

¿Es la Buprenorfina una buena opción en el manejo de dolor postoperatorio?

Background: Pain is one of the most feared outcomes of surgery by patients, yet current practices of pain management are suboptimal. Failure to address acute postoperative pain can have a variety of consequences that affect physical and psychological aspects of the patient. Current perioperative pain management normally consists of opioid therapy, which has been a mainstay for many years. However, use of opioids can have moderate risks, including nausea/vomiting, dizziness, and constipation, or more severe risks, including respiratory depression and immunosupression. Aim: In order to address some of the issues surrounding perioperative pain management, a group of key opinion leaders gathered at an international summit to analyze the current practices of perioperative pain management. One of the topics focused on buprenorphine's role in perioperative pain and the information discussed is presented throughout this article. Conclusion: Buprenorphine has been demonstrated to be effective and safe in many postoperative pain models. Its administration versatility, its manageable side effects, and its use in combination with other analgesics allow buprenorphine therapy to be successful in perioperative pain management.Antecedentes: El dolor es uno de los eventos más temidos por los pacientes después de una cirugía, y en la actualidad el manejo del dolor es subóptimo. La falta de control del dolor agudo postoperatorio puede tener una serie de consecuencias que afectan a los aspectos físicos y emocionales de los pacientes. El manejo habitual del dolor postoperatorio se basa en la utilización de opioides, pilar de tratamiento desde hace muchos años. Sin embargo, el uso de opioides puede tener riesgos moderados, como son las náuseas y vómitos, mareos y constipación, o riesgos más severos que incluyen a la inmunosupresión y depresión respiratoria. Objetivo: Para poder determinar algunos de los factores circundantes del dolor postoperatorio, se realizó una reunión cumbre internacional en la que un grupo de líderes de opinión analizó las prácticas habituales de manejo de dolor postoperatorio. Uno de los temas abordados fue el rol de la buprenorfina en el manejo del dolor perioperatorio, y la información discutida se presenta a lo largo de este artículo. Conclusión: La buprenorfina ha demostrado ser eficaz y segura en muchos modelos de dolor postoperatorio. Su versatilidad de administración, sus efectos secundarios manejables y su posibilidad de ser combinada con otros analgésicos hacen que la buprenorfina sea exitosa en el manejo del dolor perioperatorio

Non-Destructive Inspection of Anti-Corrosion Protective Coatings Using Optical Coherent Tomography

Optical Coherence Tomography (OCT) is one of the most rapidly advancing techniques. This method is capable of non-contact and non-destructive investigation of the inner structure of a broad range of materials. Compared with other methods which belong to the NDE/NDT group (Non-Destructive Evaluation/Non-Destructive Testing methods), OCT is capable of a broad range of scattering material structure visualization. Such a non-invasive and versatile method is very demanded by the industry. The authors applied the OCT method to examine the corrosion process in metal samples coated by polymer films. The main aim of the research was the evaluation of the anti-corrosion protective coatings using the OCT method. The tested samples were exposed to a harsh environment. The OCT measurements have been taken at different stages of the samples degradation. The research and tests results have been presented, as well as a brief discussion has been carried out