219 research outputs found

    Energy Test of an Efficient Random Laser Emission Collecting System

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    The problem of light collection in random lasers (RLs) is addressed. As the radiation emitted by this system is Lambertian due to its spatial incoherence, a device based on an ellipsoidal revolution mirror is designed, developed, and tested in order to optimize the harvesting of the radiation emitted by the RL. The system provides a simple injection procedure of the emitted energy at the entrance of a multimode optical fiber. The results obtained show that the device has a net energy efficiency of 35%, close to the theoretically expected one. (C) The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported LicenseThis work was supported by the Basque Government PIBA2018-24, Spanish Government MINECO under Project No. MAT2017-87035-C2-2-P (AEI/FEDER, UE), and Basque Country University (UPV/EHU) PPG17/07 and GIU17/01

    Random Laser Action in Nd:YAG Crystal Powder Jon

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    This work explores the room temperature random stimulated emission at 1.064 mu m of a Nd:YAG crystal powder (Neodymium-doped yttrium aluminum garnet) in a very simple pump configuration with no assistance from an internal mirror. The laser threshold energy as a function of pump beam area and pump wavelength has been measured, as well as the temporal dynamics of emission pulses. The absolute energy of stimulated emission and the absolute laser slope efficiency have been measured by using a method proposed by the authors. The results show a surprising high efficiency that takes the low Nd3+ ion concentration of the crystal powder into account.This work has been partially supported by the Spanish Ministerio de Economia y Competitividad, MINECO project MAT2013-48246-C2-2-P, the Basque Country Government, project IT-943-16, and Saiotek S-PE11UN072 and S-PC13UN017

    Endocannabinoid 2-Arachidonoylglycerol Synthesis and Metabolism at Neuronal Nuclear Matrix Fractions Derived from Adult Rat Brain Cortex

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    In this report, we describe the kinetics characteristics of the diacylglycerol lipase-α (DGLα) located at the nuclear matrix of nuclei derived from adult cortical neurons. Thus, using high-resolution fluorescence microscopy, classical biochemical subcellular fractionation, and Western blot techniques, we demonstrate that the DGLα enzyme is located in the matrix of neuronal nuclei. Furthermore, by quantifying the 2-arachidonoylglycerol (2-AG) level by liquid chromatography and mass spectrometry when 1-stearoyl-2-arachidonoyl-sn-glycerol (SAG) was exogenously added as substrate, we describe the presence of a mechanism for 2-AG production through DGLα dependent biosynthesis with an apparent Km (Kmapp) of 180 µM and a Vmax of 1.3 pmol min−1 µg−1 protein. We also examined the presence of enzymes with hydrolytic and oxygenase activities that are able to use 2-AG as substrate, and described the localization and compartmentalization of the major 2-AG degradation enzymes, namely monoacylglycerol lipase (MGL), fatty acid amide hydrolase (FAAH), α/β-hydrolase domain 12 protein (ABHD12) and cyclooxygenase-2 (COX2). Of these, only ABHD12 exhibited the same distribution with respect to chromatin, lamin B1, SC-35 and NeuN as that described for DGLα. When 2-AG was exogenously added, we observed the production of arachidonic acid (AA), which was prevented by inhibitors (but not specific MGL or ABHD6 inhibitors) of the ABHD family. Overall, our results expand knowledge about the subcellular distribution of neuronal DGLα, and provide biochemical and morphological evidence to ensure that 2-AG is produced in the neuronal nuclear matrix. Thus, this work paves the way for proposing a working hypothesis about the role of 2-AG produced in neuronal nuclei.This research was funded by the Spanish Ministry of Science and Innovation (Grant ID, CTQ2017-85686-R), Basque Government (Research Groups of the Basque University System, Grant IDs, IT1492-22 and IT1620-22) and Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM). Miquel Saumell-Esnaola is in receipt of a PhD contract awarded by the Department of Education of the Basque Government

    Sistema endokannabinoidea: etorkizun handiko itu terapeutikoa gaixotasun psikiatrikoetan

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    Sistema endokannabinoideak banaketa zabala dauka giza garunean, eta sistema neuromodulatzailerik garrantzitsuenetako bat izan litekeela proposatu da. Epidemiologi ikasketetan zein animali ereduetan, sistema endokannabinoidearen seinaleztapenak emozio eta kognizio funtzioak erregulatzen dituela ikusi da. Testuinguru honetan, azkeneko urteotan lan ugari bideratu dira sistema endokannabinoideak gaixotasun neuropsikiatrikoen fisiopatologian eta tratamenduan eduki dezakeen garrantzia finkatzera. Artikulu honetan, depresioa eta antsietatea bezalako gogo-aldartearen asalduretan eta eskizofrenia gaixotasunean ikusitako sistema endokannabinoidearen parte-hartzeari buruzko ebidentziak azaltzen saiatuko gara. Gaur egungo ebidentziek agerian uzten dute sistema endokannabinoideak gaixotasun psikiatrikoen azpiko zelula-prozesuetan betetzen duen funtzioa. Halere, arlo honetan asko dago ezagutzeke oraindik, eta etorkizunean sistema endokannabinoidearen gaineko ikerkuntza oso interesgarria izango da gaixotasun hauen prozesu patologikoen oinarriak ezagutzeko, edota terapiarako tresna terapeutiko berrien garapenerako

    Mutación del gen K-ras en tumores pancreático-biliares

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    Surgical outcomes of gallbladder cancer:the OMEGA retrospective, multicentre, international cohort study

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    Background: Gallbladder cancer (GBC) is rare but aggressive. The extent of surgical intervention for different GBC stages is non-uniform, ranging from cholecystectomy alone to extended resections including major hepatectomy, resection of adjacent organs and routine extrahepatic bile duct resection (EBDR). Robust evidence here is lacking, however, and survival benefit poorly defined. This study assesses factors associated with recurrence-free survival (RFS), overall survival (OS) and morbidity and mortality following GBC surgery in high income countries (HIC) and low and middle income countries (LMIC). Methods: The multicentre, retrospective Operative Management of Gallbladder Cancer (OMEGA) cohort study included all patients who underwent GBC resection across 133 centres between 1st January 2010 and 31st December 2020. Regression analyses assessed factors associated with OS, RFS and morbidity. Findings: On multivariable analysis of all 3676 patients, wedge resection and segment IVb/V resection failed to improve RFS (HR 1.04 [0.84–1.29], p = 0.711 and HR 1.18 [0.95–1.46], p = 0.13 respectively) or OS (HR 0.96 [0.79–1.17], p = 0.67 and HR 1.48 [1.16–1.88], p = 0.49 respectively), while major hepatectomy was associated with worse RFS (HR 1.33 [1.02–1.74], p = 0.037) and OS (HR 1.26 [1.03–1.53], p = 0.022). Furthermore, EBDR (OR 2.86 [2.3–3.52], p &lt; 0.0010), resection of additional organs (OR 2.22 [1.62–3.02], p &lt; 0.0010) and major hepatectomy (OR 3.81 [2.55–5.73], p &lt; 0.0010) were all associated with increased morbidity and mortality. Compared to LMIC, patients in HIC were associated with poorer RFS (HR 1.18 [1.02–1.37], p = 0.031) but not OS (HR 1.05 [0.91–1.22], p = 0.48). Adjuvant and neoadjuvant treatments were infrequently used. Interpretation: In this large, multicentre analysis of GBC surgical outcomes, liver resection was not conclusively associated with improved survival, and extended resections were associated with greater morbidity and mortality without oncological benefit. Aggressive upfront resections do not benefit higher stage GBC, and international collaborations are needed to develop evidence-based neoadjuvant and adjuvant treatment strategies to minimise surgical morbidity and prioritise prognostic benefit. Funding:Cambridge Hepatopancreatobiliary Department Research Fund.</p
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