Moving boundary and photoelastic coupling in GaAs optomechanical resonators

Chip-based cavity optomechanical systems are being considered for applications in sensing, metrology, and quantum information science. Critical to their development is an understanding of how the optical and mechanical modes interact, quantified by the coupling rate $g_{0}$. Here, we develop GaAs optomechanical resonators and investigate the moving dielectric boundary and photoelastic contributions to $g_{0}$. First, we consider coupling between the fundamental radial breathing mechanical mode and a 1550 nm band optical whispering gallery mode in microdisks. For decreasing disk radius from $R=5$ $\mu$m to $R=1$ $\mu$m, simulations and measurements show that $g_{0}$ changes from being dominated by the moving boundary contribution to having an equal photoelastic contribution. Next, we design and demonstrate nanobeam optomechanical crystals in which a $2.5$ GHz mechanical breathing mode couples to a 1550 nm optical mode predominantly through the photoelastic effect. We show a significant (30 $\%$) dependence of $g_{0}$ on the device's in-plane orientation, resulting from the difference in GaAs photoelastic coefficients along different crystalline axes, with fabricated devices exhibiting $g_{\text{0}}/2\pi$ as high as 1.1 MHz for orientation along the [110] axis. GaAs nanobeam optomechanical crystals are a promising system which can combine the demonstrated large optomechanical coupling strength with additional functionality, such as piezoelectric actuation and incorporation of optical gain media

Cooperación de Corea del Sur con Ecuador en desarrollo, a través de la transferencia de conocimientos y experiencias bajo el programa KSP (Knowledge Sharing Program)

Corea del Sur tiene su economía desarrollada con base en las asistencias internacionales después de la colonización japonesa y la guerra en la década de 1950. Al inicio estas ayudas fueron para abastecer las necesidades primarias y emergentes, luego se destinaron para recuperar y reconstruir su economía. Corea del Sur es un país que sabe y conoce la importancia de asistencia internacional. Después de haber logrado su desarrollo económico rápido, en la actualidad busca oportunidades de compartir sus conocimientos y experiencias adquiridos con los países en desarrollo mediante la cooperación internacional. Con este propósito, Corea del Sur y Ecuador trabajaron en cinco ocasiones bajo el programa KSP. Esta tesis especialmente se referirá a dos proyectos ejecutados en área de calidad con el Servicio Ecuatoriano de Calidad (INEN), mediante la coordinación del Ministerio de Industrias y Productividad (su nombre actual es Ministerio de Producción, Comercio Exterior, Inversiones y Pesca). Se explicará cómo ha funcionado el programa KSP como mecanismo de cooperación de Corea del Sur. Para ello, utilizaré fuentes de información documental, electrónica y estadística, y sobre todo pondré énfasis en las entrevistas al personal o a los expertos quienes formaron parte del equipo técnico participante en dos proyectos del KSP (Programa de Intercambio de Conocimientos) en los años 2014 y 2018. Esta investigación será descriptiva y cualitativa en la cual contendrá los procedimientos de la ejecución con sus previos pasos. Para concluir, las dos consultorías de políticas públicas realizadas mediante el programa KSP crean oportunidades de intercambiar conocimientos y experiencias que podrán servir de aporte para el desarrollo económico de Ecuador, asimismo un antecedente positivo que fortalecerá el lazo establecido entre Corea del Sur y Ecuador

Central Venous Stenosis Caused by Traction of the Innominate Vein due to a Tuberculosis-Destroyed Lung

We report a case of central venous stenosis due to a structural deformity caused by a tuberculosis-destroyed lung in a 65-year-old woman. The patient presented with left facial edema. She had a history of pulmonary tuberculosis, and the chest X-ray revealed a collapsed left lung. Angiography showed leftward deviation of the innominate vein leading to kinking and stenosis of the internal jugular vein. Stent insertion improved her facial edema

Optimizing DC Vaccination by Combination With Oncolytic Adenovirus Coexpressing IL-12 and GM-CSF

Dendritic cell (DC)-based vaccination is a promising strategy for cancer immunotherapy. However, clinical trials have indicated that immunosuppressive microenvironments induced by tumors profoundly suppress antitumor immunity and inhibit vaccine efficacy, resulting in insufficient reduction of tumor burdens. To overcome these obstacles and enhance the efficiency of DC vaccination, we generated interleukin (IL)-12- and granulocyte-macrophage colony-stimulating factor (GM-CSF)-coexpressing oncolytic adenovirus (Ad-ΔB7/IL12/GMCSF) as suitable therapeutic adjuvant to eliminate immune suppression and promote DC function. By treating tumors with Ad-ΔB7/IL12/GMCSF prior to DC vaccination, DCs elicited greater antitumor effects than in response to either treatment alone. DC migration to draining lymph nodes (DLNs) dramatically increased in mice treated with the combination therapy. This result was associated with upregulation of CC-chemokine ligand 21 (CCL21+) lymphatics in tumors treated with Ad-ΔB7/IL12/GMCSF. Moreover, the proportion of CD4+CD25+ T-cells and vascular endothelial growth factor (VEGF) expression was decreased in mice treated with the combination therapy. Furthermore, combination therapy using immature DCs also showed effective antitumor effects when combined with Ad-ΔB7/IL12/GMCSF. The combination therapy had a remarkable therapeutic efficacy on large tumors. Taken together, oncolytic adenovirus coexpressing IL-12 and GM-CSF in combination with DC vaccination has synergistic antitumor effects and can act as a potent adjuvant for promoting and optimizing DC vaccination

NFATc1 regulates the transcription of DNA damage-induced apoptosis suppressor

AbstractDNA damage induced apoptosis suppressor (DDIAS), or human Noxin (hNoxin), is strongly expressed in lung cancers. DDIAS knockdown induced apoptosis in non-small cell lung carcinoma A549 cells in response to DNA damage, indicating DDIAS as a potential therapeutic target in lung cancer. To understand the transcriptional regulation of DDIAS, we determined the transcription start site, promoter region, and transcription factor. We found that DDIAS transcription begins at nucleotide 212 upstream of the DDIAS translation start site. We cloned the DDIAS promoter region and identified NFAT2 as a major transcription factor (Im et al., 2016 [1]). We demonstrated that NFATc1 regulates DDIAS expression in both pancreatic cancer Panc-1 cells and lung cancer cells

Shock ion acceleration by an ultrashort circularly polarized laser pulse via relativistic transparency in an exploded target

We investigated ion acceleration by an electrostatic shock in an exploded target irradiated by an ultrashort, circularly polarized laser pulse by means of one- and three-dimensional particle-in-cell simulations. We discovered that the laser field penetrating via relativistic transparency (RT) rapidly heated the upstream electron plasma to enable the formation of a high-speed electrostatic shock. Owing to the RT-based rapid heating and the fast compression of the initial density spike by a circularly polarized pulse, a new regime of the shock ion acceleration driven by an ultrashort (20-40 fs), moderately intense (1-1.4 PW) laser pulse is envisaged. This regime enables more efficient shock ion acceleration under a limited total pulse energy than a linearly polarized pulse with crystal laser systems of lambda similar to 1 mu mopen